diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index 33e15d386c8..e91b78720a8 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -89,7 +89,7 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
             }
         }
 
-        self.nodes.insert(hir_id.local_id, ParentedNode { parent: self.parent_node, node: node });
+        self.nodes.insert(hir_id.local_id, ParentedNode { parent: self.parent_node, node });
     }
 
     fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_node_id: HirId, f: F) {
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 7eb0d553747..9225f19876d 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -2072,8 +2072,15 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         .map(|name| format!("function `{name}`"))
                         .unwrap_or_else(|| {
                             match &self.infcx.tcx.def_kind(self.mir_def_id()) {
+                                DefKind::Closure
+                                    if self
+                                        .infcx
+                                        .tcx
+                                        .is_coroutine(self.mir_def_id().to_def_id()) =>
+                                {
+                                    "enclosing coroutine"
+                                }
                                 DefKind::Closure => "enclosing closure",
-                                DefKind::Coroutine => "enclosing coroutine",
                                 kind => bug!("expected closure or coroutine, found {:?}", kind),
                             }
                             .to_string()
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index dff86f6343d..240a67ea1b2 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -2678,8 +2678,10 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         let typeck_root_args = ty::GenericArgs::identity_for_item(tcx, typeck_root_def_id);
 
         let parent_args = match tcx.def_kind(def_id) {
+            DefKind::Closure if tcx.is_coroutine(def_id.to_def_id()) => {
+                args.as_coroutine().parent_args()
+            }
             DefKind::Closure => args.as_closure().parent_args(),
-            DefKind::Coroutine => args.as_coroutine().parent_args(),
             DefKind::InlineConst => args.as_inline_const().parent_args(),
             other => bug!("unexpected item {:?}", other),
         };
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index c3c2f536362..2b83c787139 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -737,18 +737,6 @@ trait InferCtxtExt<'tcx> {
     ) -> T
     where
         T: TypeFoldable<TyCtxt<'tcx>>;
-
-    fn instantiate_bound_regions_with_nll_infer_vars_in_recursive_scope(
-        &self,
-        mir_def_id: LocalDefId,
-        indices: &mut UniversalRegionIndices<'tcx>,
-    );
-
-    fn instantiate_bound_regions_with_nll_infer_vars_in_item(
-        &self,
-        mir_def_id: LocalDefId,
-        indices: &mut UniversalRegionIndices<'tcx>,
-    );
 }
 
 impl<'cx, 'tcx> InferCtxtExt<'tcx> for BorrowckInferCtxt<'cx, 'tcx> {
@@ -799,54 +787,6 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for BorrowckInferCtxt<'cx, 'tcx> {
         });
         value
     }
-
-    /// Finds late-bound regions that do not appear in the parameter listing and adds them to the
-    /// indices vector. Typically, we identify late-bound regions as we process the inputs and
-    /// outputs of the closure/function. However, sometimes there are late-bound regions which do
-    /// not appear in the fn parameters but which are nonetheless in scope. The simplest case of
-    /// this are unused functions, like fn foo<'a>() { } (see e.g., #51351). Despite not being used,
-    /// users can still reference these regions (e.g., let x: &'a u32 = &22;), so we need to create
-    /// entries for them and store them in the indices map. This code iterates over the complete
-    /// set of late-bound regions and checks for any that we have not yet seen, adding them to the
-    /// inputs vector.
-    #[instrument(skip(self, indices))]
-    fn instantiate_bound_regions_with_nll_infer_vars_in_recursive_scope(
-        &self,
-        mir_def_id: LocalDefId,
-        indices: &mut UniversalRegionIndices<'tcx>,
-    ) {
-        for_each_late_bound_region_in_recursive_scope(self.tcx, mir_def_id, |r| {
-            debug!(?r);
-            if !indices.indices.contains_key(&r) {
-                let region_vid = {
-                    let name = r.get_name_or_anon();
-                    self.next_nll_region_var(FR, || RegionCtxt::LateBound(name))
-                };
-
-                debug!(?region_vid);
-                indices.insert_late_bound_region(r, region_vid.as_var());
-            }
-        });
-    }
-
-    #[instrument(skip(self, indices))]
-    fn instantiate_bound_regions_with_nll_infer_vars_in_item(
-        &self,
-        mir_def_id: LocalDefId,
-        indices: &mut UniversalRegionIndices<'tcx>,
-    ) {
-        for_each_late_bound_region_in_item(self.tcx, mir_def_id, |r| {
-            debug!(?r);
-            if !indices.indices.contains_key(&r) {
-                let region_vid = {
-                    let name = r.get_name_or_anon();
-                    self.next_nll_region_var(FR, || RegionCtxt::LateBound(name))
-                };
-
-                indices.insert_late_bound_region(r, region_vid.as_var());
-            }
-        });
-    }
 }
 
 impl<'tcx> UniversalRegionIndices<'tcx> {
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index f2be6f27ff6..51df14df644 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -373,10 +373,7 @@ fn add_unused_functions(cx: &CodegenCx<'_, '_>) {
             // just "functions", like consts, statics, etc. Filter those out.
             // If `ignore_unused_generics` was specified, filter out any
             // generic functions from consideration as well.
-            if !matches!(
-                kind,
-                DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Coroutine
-            ) {
+            if !matches!(kind, DefKind::Fn | DefKind::AssocFn | DefKind::Closure) {
                 return None;
             }
             if ignore_unused_generics && tcx.generics_of(def_id).requires_monomorphization(tcx) {
diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs
index 712b6ed5333..624ce6d8813 100644
--- a/compiler/rustc_codegen_llvm/src/type_of.rs
+++ b/compiler/rustc_codegen_llvm/src/type_of.rs
@@ -9,7 +9,7 @@ use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_target::abi::HasDataLayout;
 use rustc_target::abi::{Abi, Align, FieldsShape};
 use rustc_target::abi::{Int, Pointer, F32, F64};
-use rustc_target::abi::{PointeeInfo, Scalar, Size, TyAbiInterface, Variants};
+use rustc_target::abi::{Scalar, Size, Variants};
 use smallvec::{smallvec, SmallVec};
 
 use std::fmt::Write;
@@ -184,7 +184,6 @@ pub trait LayoutLlvmExt<'tcx> {
         immediate: bool,
     ) -> &'a Type;
     fn llvm_field_index<'a>(&self, cx: &CodegenCx<'a, 'tcx>, index: usize) -> u64;
-    fn pointee_info_at<'a>(&self, cx: &CodegenCx<'a, 'tcx>, offset: Size) -> Option<PointeeInfo>;
     fn scalar_copy_llvm_type<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> Option<&'a Type>;
 }
 
@@ -356,20 +355,6 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
         }
     }
 
-    // FIXME(eddyb) this having the same name as `TyAndLayout::pointee_info_at`
-    // (the inherent method, which is lacking this caching logic) can result in
-    // the uncached version being called - not wrong, but potentially inefficient.
-    fn pointee_info_at<'a>(&self, cx: &CodegenCx<'a, 'tcx>, offset: Size) -> Option<PointeeInfo> {
-        if let Some(&pointee) = cx.pointee_infos.borrow().get(&(self.ty, offset)) {
-            return pointee;
-        }
-
-        let result = Ty::ty_and_layout_pointee_info_at(*self, cx, offset);
-
-        cx.pointee_infos.borrow_mut().insert((self.ty, offset), result);
-        result
-    }
-
     fn scalar_copy_llvm_type<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> Option<&'a Type> {
         debug_assert!(self.is_sized());
 
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index e901eba35b7..fedd380cada 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -114,7 +114,6 @@ pub enum DefKind {
         of_trait: bool,
     },
     Closure,
-    Coroutine,
 }
 
 impl DefKind {
@@ -157,7 +156,6 @@ impl DefKind {
             DefKind::Field => "field",
             DefKind::Impl { .. } => "implementation",
             DefKind::Closure => "closure",
-            DefKind::Coroutine => "coroutine",
             DefKind::ExternCrate => "extern crate",
             DefKind::GlobalAsm => "global assembly block",
         }
@@ -216,7 +214,6 @@ impl DefKind {
             | DefKind::LifetimeParam
             | DefKind::ExternCrate
             | DefKind::Closure
-            | DefKind::Coroutine
             | DefKind::Use
             | DefKind::ForeignMod
             | DefKind::GlobalAsm
@@ -226,7 +223,7 @@ impl DefKind {
 
     #[inline]
     pub fn is_fn_like(self) -> bool {
-        matches!(self, DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Coroutine)
+        matches!(self, DefKind::Fn | DefKind::AssocFn | DefKind::Closure)
     }
 
     /// Whether `query get_codegen_attrs` should be used with this definition.
@@ -236,7 +233,6 @@ impl DefKind {
             | DefKind::AssocFn
             | DefKind::Ctor(..)
             | DefKind::Closure
-            | DefKind::Coroutine
             | DefKind::Static(_) => true,
             DefKind::Mod
             | DefKind::Struct
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index b279564ed45..fbed6f33e59 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -1449,7 +1449,7 @@ fn opaque_type_cycle_error(
                         label_match(capture.place.ty(), capture.get_path_span(tcx));
                     }
                     // Label any coroutine locals that capture the opaque
-                    if let DefKind::Coroutine = tcx.def_kind(closure_def_id)
+                    if tcx.is_coroutine(closure_def_id)
                         && let Some(coroutine_layout) = tcx.mir_coroutine_witnesses(closure_def_id)
                     {
                         for interior_ty in &coroutine_layout.field_tys {
@@ -1470,7 +1470,7 @@ pub(super) fn check_coroutine_obligations(
     tcx: TyCtxt<'_>,
     def_id: LocalDefId,
 ) -> Result<(), ErrorGuaranteed> {
-    debug_assert!(matches!(tcx.def_kind(def_id), DefKind::Coroutine));
+    debug_assert!(tcx.is_coroutine(def_id.to_def_id()));
 
     let typeck = tcx.typeck(def_id);
     let param_env = tcx.param_env(def_id);
diff --git a/compiler/rustc_hir_typeck/src/mem_categorization.rs b/compiler/rustc_hir_typeck/src/mem_categorization.rs
index b25830675b2..94da4bfcdc4 100644
--- a/compiler/rustc_hir_typeck/src/mem_categorization.rs
+++ b/compiler/rustc_hir_typeck/src/mem_categorization.rs
@@ -66,25 +66,18 @@ use rustc_trait_selection::infer::InferCtxtExt;
 
 pub(crate) trait HirNode {
     fn hir_id(&self) -> hir::HirId;
-    fn span(&self) -> Span;
 }
 
 impl HirNode for hir::Expr<'_> {
     fn hir_id(&self) -> hir::HirId {
         self.hir_id
     }
-    fn span(&self) -> Span {
-        self.span
-    }
 }
 
 impl HirNode for hir::Pat<'_> {
     fn hir_id(&self) -> hir::HirId {
         self.hir_id
     }
-    fn span(&self) -> Span {
-        self.span
-    }
 }
 
 #[derive(Clone)]
diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
index c8049164391..ee6a3fd0c82 100644
--- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs
+++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
@@ -113,9 +113,6 @@ pub trait TypeRelatingDelegate<'tcx> {
     fn forbid_inference_vars() -> bool;
 }
 
-#[derive(Copy, Clone)]
-struct UniversallyQuantified(bool);
-
 impl<'me, 'tcx, D> TypeRelating<'me, 'tcx, D>
 where
     D: TypeRelatingDelegate<'tcx>,
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 99bea647bd5..4648d83a6f3 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -756,7 +756,7 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
     });
 
     tcx.hir().par_body_owners(|def_id| {
-        if let rustc_hir::def::DefKind::Coroutine = tcx.def_kind(def_id) {
+        if tcx.is_coroutine(def_id.to_def_id()) {
             tcx.ensure().mir_coroutine_witnesses(def_id);
             tcx.ensure().check_coroutine_obligations(def_id);
         }
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index d697f23d230..765bb7a362e 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -857,8 +857,7 @@ fn should_encode_span(def_kind: DefKind) -> bool {
         | DefKind::OpaqueTy
         | DefKind::Field
         | DefKind::Impl { .. }
-        | DefKind::Closure
-        | DefKind::Coroutine => true,
+        | DefKind::Closure => true,
         DefKind::ForeignMod | DefKind::GlobalAsm => false,
     }
 }
@@ -898,8 +897,7 @@ fn should_encode_attrs(def_kind: DefKind) -> bool {
         | DefKind::InlineConst
         | DefKind::OpaqueTy
         | DefKind::LifetimeParam
-        | DefKind::GlobalAsm
-        | DefKind::Coroutine => false,
+        | DefKind::GlobalAsm => false,
     }
 }
 
@@ -934,8 +932,7 @@ fn should_encode_expn_that_defined(def_kind: DefKind) -> bool {
         | DefKind::Field
         | DefKind::LifetimeParam
         | DefKind::GlobalAsm
-        | DefKind::Closure
-        | DefKind::Coroutine => false,
+        | DefKind::Closure => false,
     }
 }
 
@@ -970,7 +967,6 @@ fn should_encode_visibility(def_kind: DefKind) -> bool {
         | DefKind::GlobalAsm
         | DefKind::Impl { .. }
         | DefKind::Closure
-        | DefKind::Coroutine
         | DefKind::ExternCrate => false,
     }
 }
@@ -1006,7 +1002,6 @@ fn should_encode_stability(def_kind: DefKind) -> bool {
         | DefKind::InlineConst
         | DefKind::GlobalAsm
         | DefKind::Closure
-        | DefKind::Coroutine
         | DefKind::ExternCrate => false,
     }
 }
@@ -1049,6 +1044,8 @@ fn should_encode_mir(
         | DefKind::AssocConst
         | DefKind::Static(..)
         | DefKind::Const => (true, false),
+        // Coroutines require optimized MIR to compute layout.
+        DefKind::Closure if tcx.is_coroutine(def_id.to_def_id()) => (false, true),
         // Full-fledged functions + closures
         DefKind::AssocFn | DefKind::Fn | DefKind::Closure => {
             let generics = tcx.generics_of(def_id);
@@ -1062,8 +1059,6 @@ fn should_encode_mir(
                 || tcx.is_const_default_method(def_id.to_def_id());
             (is_const_fn, opt)
         }
-        // Coroutines require optimized MIR to compute layout.
-        DefKind::Coroutine => (false, true),
         // The others don't have MIR.
         _ => (false, false),
     }
@@ -1099,7 +1094,6 @@ fn should_encode_variances<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, def_kind: Def
         | DefKind::InlineConst
         | DefKind::GlobalAsm
         | DefKind::Closure
-        | DefKind::Coroutine
         | DefKind::ExternCrate => false,
         DefKind::TyAlias => tcx.type_alias_is_lazy(def_id),
     }
@@ -1128,8 +1122,7 @@ fn should_encode_generics(def_kind: DefKind) -> bool {
         | DefKind::Impl { .. }
         | DefKind::Field
         | DefKind::TyParam
-        | DefKind::Closure
-        | DefKind::Coroutine => true,
+        | DefKind::Closure => true,
         DefKind::Mod
         | DefKind::ForeignMod
         | DefKind::ConstParam
@@ -1158,7 +1151,6 @@ fn should_encode_type(tcx: TyCtxt<'_>, def_id: LocalDefId, def_kind: DefKind) ->
         | DefKind::AssocFn
         | DefKind::AssocConst
         | DefKind::Closure
-        | DefKind::Coroutine
         | DefKind::ConstParam
         | DefKind::AnonConst
         | DefKind::InlineConst => true,
@@ -1219,7 +1211,6 @@ fn should_encode_fn_sig(def_kind: DefKind) -> bool {
         | DefKind::Impl { .. }
         | DefKind::AssocConst
         | DefKind::Closure
-        | DefKind::Coroutine
         | DefKind::ConstParam
         | DefKind::AnonConst
         | DefKind::InlineConst
@@ -1258,7 +1249,6 @@ fn should_encode_constness(def_kind: DefKind) -> bool {
         | DefKind::OpaqueTy
         | DefKind::Impl { of_trait: false }
         | DefKind::ForeignTy
-        | DefKind::Coroutine
         | DefKind::ConstParam
         | DefKind::InlineConst
         | DefKind::AssocTy
@@ -1293,7 +1283,6 @@ fn should_encode_const(def_kind: DefKind) -> bool {
         | DefKind::Impl { .. }
         | DefKind::AssocFn
         | DefKind::Closure
-        | DefKind::Coroutine
         | DefKind::ConstParam
         | DefKind::AssocTy
         | DefKind::TyParam
@@ -1453,8 +1442,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                     self.encode_info_for_assoc_item(def_id);
                 }
             }
-            if let DefKind::Coroutine = def_kind {
-                let data = self.tcx.coroutine_kind(def_id).unwrap();
+            if def_kind == DefKind::Closure
+                && let Some(data) = self.tcx.coroutine_kind(def_id)
+            {
                 record!(self.tables.coroutine_kind[def_id] <- data);
             }
             if let DefKind::Enum | DefKind::Struct | DefKind::Union = def_kind {
@@ -1636,7 +1626,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.closure_saved_names_of_captured_variables[def_id.to_def_id()]
                     <- tcx.closure_saved_names_of_captured_variables(def_id));
 
-                if let DefKind::Coroutine = self.tcx.def_kind(def_id)
+                if self.tcx.is_coroutine(def_id.to_def_id())
                     && let Some(witnesses) = tcx.mir_coroutine_witnesses(def_id)
                 {
                     record!(self.tables.mir_coroutine_witnesses[def_id.to_def_id()] <- witnesses);
@@ -1663,7 +1653,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             record!(self.tables.promoted_mir[def_id.to_def_id()] <- tcx.promoted_mir(def_id));
 
-            if let DefKind::Coroutine = self.tcx.def_kind(def_id)
+            if self.tcx.is_coroutine(def_id.to_def_id())
                 && let Some(witnesses) = tcx.mir_coroutine_witnesses(def_id)
             {
                 record!(self.tables.mir_coroutine_witnesses[def_id.to_def_id()] <- witnesses);
diff --git a/compiler/rustc_metadata/src/rmeta/table.rs b/compiler/rustc_metadata/src/rmeta/table.rs
index 96cf668b7da..7cdbcd9193c 100644
--- a/compiler/rustc_metadata/src/rmeta/table.rs
+++ b/compiler/rustc_metadata/src/rmeta/table.rs
@@ -167,7 +167,6 @@ fixed_size_enum! {
         ( Impl { of_trait: false }                 )
         ( Impl { of_trait: true }                  )
         ( Closure                                  )
-        ( Coroutine                                )
         ( Static(ast::Mutability::Not)             )
         ( Static(ast::Mutability::Mut)             )
         ( Ctor(CtorOf::Struct, CtorKind::Fn)       )
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 9103187acf3..7bf0da2f2f3 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -231,8 +231,7 @@ impl<'hir> Map<'hir> {
             Node::ConstBlock(_) => DefKind::InlineConst,
             Node::Field(_) => DefKind::Field,
             Node::Expr(expr) => match expr.kind {
-                ExprKind::Closure(Closure { movability: None, .. }) => DefKind::Closure,
-                ExprKind::Closure(Closure { movability: Some(_), .. }) => DefKind::Coroutine,
+                ExprKind::Closure(_) => DefKind::Closure,
                 _ => bug!("def_kind: unsupported node: {}", self.node_to_string(hir_id)),
             },
             Node::GenericParam(param) => match param.kind {
@@ -436,7 +435,7 @@ impl<'hir> Map<'hir> {
             }
             DefKind::InlineConst => BodyOwnerKind::Const { inline: true },
             DefKind::Ctor(..) | DefKind::Fn | DefKind::AssocFn => BodyOwnerKind::Fn,
-            DefKind::Closure | DefKind::Coroutine => BodyOwnerKind::Closure,
+            DefKind::Closure => BodyOwnerKind::Closure,
             DefKind::Static(mt) => BodyOwnerKind::Static(mt),
             dk => bug!("{:?} is not a body node: {:?}", def_id, dk),
         }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index bb7f0315ebd..4ded61daa5c 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -804,6 +804,10 @@ impl<'tcx> TyCtxt<'tcx> {
         self.diagnostic_items(did.krate).name_to_id.get(&name) == Some(&did)
     }
 
+    pub fn is_coroutine(self, def_id: DefId) -> bool {
+        self.coroutine_kind(def_id).is_some()
+    }
+
     /// Returns `true` if the node pointed to by `def_id` is a coroutine for an async construct.
     pub fn coroutine_is_async(self, def_id: DefId) -> bool {
         matches!(self.coroutine_kind(def_id), Some(hir::CoroutineKind::Async(_)))
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 77cf3c0041c..cbf1a9900d9 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -550,16 +550,13 @@ impl<'tcx> TyCtxt<'tcx> {
     /// those are not yet phased out). The parent of the closure's
     /// `DefId` will also be the context where it appears.
     pub fn is_closure(self, def_id: DefId) -> bool {
-        matches!(self.def_kind(def_id), DefKind::Closure | DefKind::Coroutine)
+        matches!(self.def_kind(def_id), DefKind::Closure)
     }
 
     /// Returns `true` if `def_id` refers to a definition that does not have its own
     /// type-checking context, i.e. closure, coroutine or inline const.
     pub fn is_typeck_child(self, def_id: DefId) -> bool {
-        matches!(
-            self.def_kind(def_id),
-            DefKind::Closure | DefKind::Coroutine | DefKind::InlineConst
-        )
+        matches!(self.def_kind(def_id), DefKind::Closure | DefKind::InlineConst)
     }
 
     /// Returns `true` if `def_id` refers to a trait (i.e., `trait Foo { ... }`).
@@ -732,11 +729,13 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn def_kind_descr(self, def_kind: DefKind, def_id: DefId) -> &'static str {
         match def_kind {
             DefKind::AssocFn if self.associated_item(def_id).fn_has_self_parameter => "method",
-            DefKind::Coroutine => match self.coroutine_kind(def_id).unwrap() {
-                rustc_hir::CoroutineKind::Async(..) => "async closure",
-                rustc_hir::CoroutineKind::Coroutine => "coroutine",
-                rustc_hir::CoroutineKind::Gen(..) => "gen closure",
-            },
+            DefKind::Closure if let Some(coroutine_kind) = self.coroutine_kind(def_id) => {
+                match coroutine_kind {
+                    rustc_hir::CoroutineKind::Async(..) => "async closure",
+                    rustc_hir::CoroutineKind::Coroutine => "coroutine",
+                    rustc_hir::CoroutineKind::Gen(..) => "gen closure",
+                }
+            }
             _ => def_kind.descr(def_id),
         }
     }
@@ -750,11 +749,13 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn def_kind_descr_article(self, def_kind: DefKind, def_id: DefId) -> &'static str {
         match def_kind {
             DefKind::AssocFn if self.associated_item(def_id).fn_has_self_parameter => "a",
-            DefKind::Coroutine => match self.coroutine_kind(def_id).unwrap() {
-                rustc_hir::CoroutineKind::Async(..) => "an",
-                rustc_hir::CoroutineKind::Coroutine => "a",
-                rustc_hir::CoroutineKind::Gen(..) => "a",
-            },
+            DefKind::Closure if let Some(coroutine_kind) = self.coroutine_kind(def_id) => {
+                match coroutine_kind {
+                    rustc_hir::CoroutineKind::Async(..) => "an",
+                    rustc_hir::CoroutineKind::Coroutine => "a",
+                    rustc_hir::CoroutineKind::Gen(..) => "a",
+                }
+            }
             _ => def_kind.article(),
         }
     }
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index ad06db91e37..19b6496b102 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -638,6 +638,14 @@ fn construct_error(tcx: TyCtxt<'_>, def_id: LocalDefId, guar: ErrorGuaranteed) -
             );
             (sig.inputs().to_vec(), sig.output(), None)
         }
+        DefKind::Closure if coroutine_kind.is_some() => {
+            let coroutine_ty = tcx.type_of(def_id).instantiate_identity();
+            let ty::Coroutine(_, args, _) = coroutine_ty.kind() else { bug!() };
+            let args = args.as_coroutine();
+            let yield_ty = args.yield_ty();
+            let return_ty = args.return_ty();
+            (vec![coroutine_ty, args.resume_ty()], return_ty, Some(yield_ty))
+        }
         DefKind::Closure => {
             let closure_ty = tcx.type_of(def_id).instantiate_identity();
             let ty::Closure(_, args) = closure_ty.kind() else { bug!() };
@@ -650,14 +658,6 @@ fn construct_error(tcx: TyCtxt<'_>, def_id: LocalDefId, guar: ErrorGuaranteed) -
             };
             ([self_ty].into_iter().chain(sig.inputs().to_vec()).collect(), sig.output(), None)
         }
-        DefKind::Coroutine => {
-            let coroutine_ty = tcx.type_of(def_id).instantiate_identity();
-            let ty::Coroutine(_, args, _) = coroutine_ty.kind() else { bug!() };
-            let args = args.as_coroutine();
-            let yield_ty = args.yield_ty();
-            let return_ty = args.return_ty();
-            (vec![coroutine_ty, args.resume_ty()], return_ty, Some(yield_ty))
-        }
         dk => bug!("{:?} is not a body: {:?}", def_id, dk),
     };
 
diff --git a/compiler/rustc_mir_build/src/thir/cx/mod.rs b/compiler/rustc_mir_build/src/thir/cx/mod.rs
index 708e0b31b9e..4eba7103c0c 100644
--- a/compiler/rustc_mir_build/src/thir/cx/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/mod.rs
@@ -37,7 +37,7 @@ pub(crate) fn thir_body(
 
         // The resume argument may be missing, in that case we need to provide it here.
         // It will always be `()` in this case.
-        if tcx.def_kind(owner_def) == DefKind::Coroutine && body.params.is_empty() {
+        if tcx.is_coroutine(owner_def.to_def_id()) && body.params.is_empty() {
             cx.thir.params.push(Param {
                 ty: Ty::new_unit(tcx),
                 pat: None,
@@ -119,6 +119,17 @@ impl<'tcx> Cx<'tcx> {
 
     fn closure_env_param(&self, owner_def: LocalDefId, owner_id: HirId) -> Option<Param<'tcx>> {
         match self.tcx.def_kind(owner_def) {
+            DefKind::Closure if self.tcx.is_coroutine(owner_def.to_def_id()) => {
+                let coroutine_ty = self.typeck_results.node_type(owner_id);
+                let coroutine_param = Param {
+                    ty: coroutine_ty,
+                    pat: None,
+                    ty_span: None,
+                    self_kind: None,
+                    hir_id: None,
+                };
+                Some(coroutine_param)
+            }
             DefKind::Closure => {
                 let closure_ty = self.typeck_results.node_type(owner_id);
 
@@ -148,17 +159,6 @@ impl<'tcx> Cx<'tcx> {
 
                 Some(env_param)
             }
-            DefKind::Coroutine => {
-                let coroutine_ty = self.typeck_results.node_type(owner_id);
-                let coroutine_param = Param {
-                    ty: coroutine_ty,
-                    pat: None,
-                    ty_span: None,
-                    self_kind: None,
-                    hir_id: None,
-                };
-                Some(coroutine_param)
-            }
             _ => None,
         }
     }
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
index d80497fd45f..8b2a96cff41 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -18,17 +18,14 @@ use rustc_hir::pat_util::EnumerateAndAdjustIterator;
 use rustc_hir::RangeEnd;
 use rustc_index::Idx;
 use rustc_middle::mir::interpret::{ErrorHandled, GlobalId, LitToConstError, LitToConstInput};
-use rustc_middle::mir::{self, BorrowKind, Const, Mutability, UserTypeProjection};
+use rustc_middle::mir::{self, BorrowKind, Const, Mutability};
 use rustc_middle::thir::{
     Ascription, BindingMode, FieldPat, LocalVarId, Pat, PatKind, PatRange, PatRangeBoundary,
 };
 use rustc_middle::ty::layout::IntegerExt;
-use rustc_middle::ty::{
-    self, AdtDef, CanonicalUserTypeAnnotation, GenericArg, GenericArgsRef, Region, Ty, TyCtxt,
-    TypeVisitableExt, UserType,
-};
+use rustc_middle::ty::{self, CanonicalUserTypeAnnotation, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::def_id::LocalDefId;
-use rustc_span::{ErrorGuaranteed, Span, Symbol};
+use rustc_span::{ErrorGuaranteed, Span};
 use rustc_target::abi::{FieldIdx, Integer};
 
 use std::cmp::Ordering;
@@ -701,146 +698,3 @@ impl<'tcx> UserAnnotatedTyHelpers<'tcx> for PatCtxt<'_, 'tcx> {
         self.typeck_results
     }
 }
-
-trait PatternFoldable<'tcx>: Sized {
-    fn fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        self.super_fold_with(folder)
-    }
-
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self;
-}
-
-trait PatternFolder<'tcx>: Sized {
-    fn fold_pattern(&mut self, pattern: &Pat<'tcx>) -> Pat<'tcx> {
-        pattern.super_fold_with(self)
-    }
-
-    fn fold_pattern_kind(&mut self, kind: &PatKind<'tcx>) -> PatKind<'tcx> {
-        kind.super_fold_with(self)
-    }
-}
-
-impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Box<T> {
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        let content: T = (**self).fold_with(folder);
-        Box::new(content)
-    }
-}
-
-impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Vec<T> {
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        self.iter().map(|t| t.fold_with(folder)).collect()
-    }
-}
-
-impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Box<[T]> {
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        self.iter().map(|t| t.fold_with(folder)).collect()
-    }
-}
-
-impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Option<T> {
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        self.as_ref().map(|t| t.fold_with(folder))
-    }
-}
-
-macro_rules! ClonePatternFoldableImpls {
-    (<$lt_tcx:tt> $($ty:ty),+) => {
-        $(
-            impl<$lt_tcx> PatternFoldable<$lt_tcx> for $ty {
-                fn super_fold_with<F: PatternFolder<$lt_tcx>>(&self, _: &mut F) -> Self {
-                    Clone::clone(self)
-                }
-            }
-        )+
-    }
-}
-
-ClonePatternFoldableImpls! { <'tcx>
-    Span, FieldIdx, Mutability, Symbol, LocalVarId, usize,
-    Region<'tcx>, Ty<'tcx>, BindingMode, AdtDef<'tcx>,
-    GenericArgsRef<'tcx>, &'tcx GenericArg<'tcx>, UserType<'tcx>,
-    UserTypeProjection, CanonicalUserTypeAnnotation<'tcx>
-}
-
-impl<'tcx> PatternFoldable<'tcx> for FieldPat<'tcx> {
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        FieldPat { field: self.field.fold_with(folder), pattern: self.pattern.fold_with(folder) }
-    }
-}
-
-impl<'tcx> PatternFoldable<'tcx> for Pat<'tcx> {
-    fn fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        folder.fold_pattern(self)
-    }
-
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        Pat {
-            ty: self.ty.fold_with(folder),
-            span: self.span.fold_with(folder),
-            kind: self.kind.fold_with(folder),
-        }
-    }
-}
-
-impl<'tcx> PatternFoldable<'tcx> for PatKind<'tcx> {
-    fn fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        folder.fold_pattern_kind(self)
-    }
-
-    fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        match *self {
-            PatKind::Wild => PatKind::Wild,
-            PatKind::Error(e) => PatKind::Error(e),
-            PatKind::AscribeUserType {
-                ref subpattern,
-                ascription: Ascription { ref annotation, variance },
-            } => PatKind::AscribeUserType {
-                subpattern: subpattern.fold_with(folder),
-                ascription: Ascription { annotation: annotation.fold_with(folder), variance },
-            },
-            PatKind::Binding { mutability, name, mode, var, ty, ref subpattern, is_primary } => {
-                PatKind::Binding {
-                    mutability: mutability.fold_with(folder),
-                    name: name.fold_with(folder),
-                    mode: mode.fold_with(folder),
-                    var: var.fold_with(folder),
-                    ty: ty.fold_with(folder),
-                    subpattern: subpattern.fold_with(folder),
-                    is_primary,
-                }
-            }
-            PatKind::Variant { adt_def, args, variant_index, ref subpatterns } => {
-                PatKind::Variant {
-                    adt_def: adt_def.fold_with(folder),
-                    args: args.fold_with(folder),
-                    variant_index,
-                    subpatterns: subpatterns.fold_with(folder),
-                }
-            }
-            PatKind::Leaf { ref subpatterns } => {
-                PatKind::Leaf { subpatterns: subpatterns.fold_with(folder) }
-            }
-            PatKind::Deref { ref subpattern } => {
-                PatKind::Deref { subpattern: subpattern.fold_with(folder) }
-            }
-            PatKind::Constant { value } => PatKind::Constant { value },
-            PatKind::InlineConstant { def, subpattern: ref pattern } => {
-                PatKind::InlineConstant { def, subpattern: pattern.fold_with(folder) }
-            }
-            PatKind::Range(ref range) => PatKind::Range(range.clone()),
-            PatKind::Slice { ref prefix, ref slice, ref suffix } => PatKind::Slice {
-                prefix: prefix.fold_with(folder),
-                slice: slice.fold_with(folder),
-                suffix: suffix.fold_with(folder),
-            },
-            PatKind::Array { ref prefix, ref slice, ref suffix } => PatKind::Array {
-                prefix: prefix.fold_with(folder),
-                slice: slice.fold_with(folder),
-                suffix: suffix.fold_with(folder),
-            },
-            PatKind::Or { ref pats } => PatKind::Or { pats: pats.fold_with(folder) },
-        }
-    }
-}
diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index 42d33f4f517..9a16003bdc9 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -84,8 +84,7 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
 
         // FIXME(welseywiser) const prop doesn't work on coroutines because of query cycles
         // computing their layout.
-        let is_coroutine = def_kind == DefKind::Coroutine;
-        if is_coroutine {
+        if tcx.is_coroutine(def_id.to_def_id()) {
             trace!("ConstProp skipped for coroutine {:?}", def_id);
             return;
         }
diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs
index da315bb86ac..99eecb567f2 100644
--- a/compiler/rustc_mir_transform/src/const_prop_lint.rs
+++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs
@@ -61,7 +61,7 @@ impl<'tcx> MirLint<'tcx> for ConstPropLint {
 
         // FIXME(welseywiser) const prop doesn't work on coroutines because of query cycles
         // computing their layout.
-        if let DefKind::Coroutine = def_kind {
+        if tcx.is_coroutine(def_id.to_def_id()) {
             trace!("ConstPropLint skipped for coroutine {:?}", def_id);
             return;
         }
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 5c05446a981..fff760ba399 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -395,7 +395,7 @@ fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: LocalDefId) -> Body<'_> {
 /// mir borrowck *before* doing so in order to ensure that borrowck can be run and doesn't
 /// end up missing the source MIR due to stealing happening.
 fn mir_drops_elaborated_and_const_checked(tcx: TyCtxt<'_>, def: LocalDefId) -> &Steal<Body<'_>> {
-    if let DefKind::Coroutine = tcx.def_kind(def) {
+    if tcx.is_coroutine(def.to_def_id()) {
         tcx.ensure_with_value().mir_coroutine_witnesses(def);
     }
     let mir_borrowck = tcx.mir_borrowck(def);
diff --git a/compiler/rustc_monomorphize/src/polymorphize.rs b/compiler/rustc_monomorphize/src/polymorphize.rs
index a3b35eab465..91abbb216d6 100644
--- a/compiler/rustc_monomorphize/src/polymorphize.rs
+++ b/compiler/rustc_monomorphize/src/polymorphize.rs
@@ -131,7 +131,7 @@ fn mark_used_by_default_parameters<'tcx>(
     unused_parameters: &mut UnusedGenericParams,
 ) {
     match tcx.def_kind(def_id) {
-        DefKind::Closure | DefKind::Coroutine => {
+        DefKind::Closure => {
             for param in &generics.params {
                 debug!(?param, "(closure/gen)");
                 unused_parameters.mark_used(param.index);
@@ -248,7 +248,7 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkUsedGenericParams<'a, 'tcx> {
     fn visit_local_decl(&mut self, local: Local, local_decl: &LocalDecl<'tcx>) {
         if local == Local::from_usize(1) {
             let def_kind = self.tcx.def_kind(self.def_id);
-            if matches!(def_kind, DefKind::Closure | DefKind::Coroutine) {
+            if matches!(def_kind, DefKind::Closure) {
                 // Skip visiting the closure/coroutine that is currently being processed. This only
                 // happens because the first argument to the closure is a reference to itself and
                 // that will call `visit_args`, resulting in each generic parameter captured being
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index b78c8b849f7..b8109d5bb06 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -653,8 +653,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
             | DefKind::Field
             | DefKind::GlobalAsm
             | DefKind::Impl { .. }
-            | DefKind::Closure
-            | DefKind::Coroutine => (),
+            | DefKind::Closure => (),
         }
     }
 }
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index 60a28e3a1a4..65901eedb21 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -973,8 +973,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 | DefKind::LifetimeParam
                 | DefKind::GlobalAsm
                 | DefKind::Closure
-                | DefKind::Impl { .. }
-                | DefKind::Coroutine,
+                | DefKind::Impl { .. },
                 _,
             )
             | Res::Local(..)
diff --git a/compiler/rustc_smir/src/rustc_smir/mod.rs b/compiler/rustc_smir/src/rustc_smir/mod.rs
index 5d903e69c6c..eee587f3b2a 100644
--- a/compiler/rustc_smir/src/rustc_smir/mod.rs
+++ b/compiler/rustc_smir/src/rustc_smir/mod.rs
@@ -89,7 +89,7 @@ pub(crate) fn new_item_kind(kind: DefKind) -> ItemKind {
         | DefKind::GlobalAsm => {
             unreachable!("Not a valid item kind: {kind:?}");
         }
-        DefKind::Closure | DefKind::Coroutine | DefKind::AssocFn | DefKind::Fn => ItemKind::Fn,
+        DefKind::Closure | DefKind::AssocFn | DefKind::Fn => ItemKind::Fn,
         DefKind::Const | DefKind::InlineConst | DefKind::AssocConst | DefKind::AnonConst => {
             ItemKind::Const
         }
diff --git a/compiler/rustc_symbol_mangling/src/lib.rs b/compiler/rustc_symbol_mangling/src/lib.rs
index 9f0982d0995..311b94d9e0e 100644
--- a/compiler/rustc_symbol_mangling/src/lib.rs
+++ b/compiler/rustc_symbol_mangling/src/lib.rs
@@ -234,7 +234,7 @@ fn compute_symbol_name<'tcx>(
     // and we want to be sure to avoid any symbol conflicts here.
     let is_globally_shared_function = matches!(
         tcx.def_kind(instance.def_id()),
-        DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Coroutine | DefKind::Ctor(..)
+        DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Ctor(..)
     ) && matches!(
         MonoItem::Fn(instance).instantiation_mode(tcx),
         InstantiationMode::GloballyShared { may_conflict: true }
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
index 59c979cf437..eb30b4cd85e 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
@@ -37,8 +37,6 @@ pub(super) trait GoalKind<'tcx>:
 
     fn trait_ref(self, tcx: TyCtxt<'tcx>) -> ty::TraitRef<'tcx>;
 
-    fn polarity(self) -> ty::ImplPolarity;
-
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self;
 
     fn trait_def_id(self, tcx: TyCtxt<'tcx>) -> DefId;
diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs
index 0cf4799f86d..b526fa19c13 100644
--- a/compiler/rustc_trait_selection/src/solve/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/mod.rs
@@ -64,8 +64,6 @@ enum GoalEvaluationKind {
 
 trait CanonicalResponseExt {
     fn has_no_inference_or_external_constraints(&self) -> bool;
-
-    fn has_only_region_constraints(&self) -> bool;
 }
 
 impl<'tcx> CanonicalResponseExt for Canonical<'tcx, Response<'tcx>> {
@@ -74,11 +72,6 @@ impl<'tcx> CanonicalResponseExt for Canonical<'tcx, Response<'tcx>> {
             && self.value.var_values.is_identity()
             && self.value.external_constraints.opaque_types.is_empty()
     }
-
-    fn has_only_region_constraints(&self) -> bool {
-        self.value.var_values.is_identity_modulo_regions()
-            && self.value.external_constraints.opaque_types.is_empty()
-    }
 }
 
 impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs b/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs
index 6c29ce492df..37bbf32c768 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs
@@ -101,10 +101,6 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
         self.projection_ty.trait_ref(tcx)
     }
 
-    fn polarity(self) -> ty::ImplPolarity {
-        ty::ImplPolarity::Positive
-    }
-
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self {
         self.with_self_ty(tcx, self_ty)
     }
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index a0c065dfa03..95712da3c5e 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -24,10 +24,6 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         self.trait_ref
     }
 
-    fn polarity(self) -> ty::ImplPolarity {
-        self.polarity
-    }
-
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self {
         self.with_self_ty(tcx, self_ty)
     }
diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs
index 6cf5aa6f2fb..eef90dc6dac 100644
--- a/compiler/rustc_ty_utils/src/implied_bounds.rs
+++ b/compiler/rustc_ty_utils/src/implied_bounds.rs
@@ -156,8 +156,7 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'
         | DefKind::Field
         | DefKind::LifetimeParam
         | DefKind::GlobalAsm
-        | DefKind::Closure
-        | DefKind::Coroutine => ty::List::empty(),
+        | DefKind::Closure => ty::List::empty(),
     }
 }
 
diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs
index c17970e23a2..16f5ed09d00 100644
--- a/compiler/rustc_ty_utils/src/opaque_types.rs
+++ b/compiler/rustc_ty_utils/src/opaque_types.rs
@@ -313,7 +313,7 @@ fn opaque_types_defined_by<'tcx>(
         | DefKind::Impl { .. } => {}
         // Closures and coroutines are type checked with their parent, so we need to allow all
         // opaques from the closure signature *and* from the parent body.
-        DefKind::Closure | DefKind::Coroutine | DefKind::InlineConst => {
+        DefKind::Closure | DefKind::InlineConst => {
             collector.opaques.extend(tcx.opaque_types_defined_by(tcx.local_parent(item)));
         }
     }
diff --git a/compiler/rustc_ty_utils/src/sig_types.rs b/compiler/rustc_ty_utils/src/sig_types.rs
index 268639a7f44..7c0261c818f 100644
--- a/compiler/rustc_ty_utils/src/sig_types.rs
+++ b/compiler/rustc_ty_utils/src/sig_types.rs
@@ -67,7 +67,7 @@ pub(crate) fn walk_types<'tcx, V: SpannedTypeVisitor<'tcx>>(
         // These are not part of a public API, they can only appear as hidden types, and there
         // the interesting parts are solely in the signature of the containing item's opaque type
         // or dyn type.
-        DefKind::InlineConst | DefKind::Closure | DefKind::Coroutine => {}
+        DefKind::InlineConst | DefKind::Closure => {}
         DefKind::Impl { of_trait } => {
             if of_trait {
                 let span = tcx.hir().get_by_def_id(item).expect_item().expect_impl().of_trait.unwrap().path.span;
diff --git a/library/std/src/error.rs b/library/std/src/error.rs
index 375ff2d2450..b240e4e2c45 100644
--- a/library/std/src/error.rs
+++ b/library/std/src/error.rs
@@ -12,14 +12,6 @@ pub use core::error::Error;
 #[unstable(feature = "error_generic_member_access", issue = "99301")]
 pub use core::error::{request_ref, request_value, Request};
 
-mod private {
-    // This is a hack to prevent `type_id` from being overridden by `Error`
-    // implementations, since that can enable unsound downcasting.
-    #[unstable(feature = "error_type_id", issue = "60784")]
-    #[derive(Debug)]
-    pub struct Internal;
-}
-
 /// An error reporter that prints an error and its sources.
 ///
 /// Report also exposes configuration options for formatting the error sources, either entirely on a
diff --git a/src/librustdoc/formats/item_type.rs b/src/librustdoc/formats/item_type.rs
index 5666751d1ce..e80da46adb4 100644
--- a/src/librustdoc/formats/item_type.rs
+++ b/src/librustdoc/formats/item_type.rs
@@ -149,8 +149,7 @@ impl From<DefKind> for ItemType {
             | DefKind::LifetimeParam
             | DefKind::GlobalAsm
             | DefKind::Impl { .. }
-            | DefKind::Closure
-            | DefKind::Coroutine => Self::ForeignType,
+            | DefKind::Closure => Self::ForeignType,
         }
     }
 }
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 615fb08c76f..7cc0f2e8f1e 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -25,19 +25,9 @@ function showMain() {
     removeClass(document.getElementById(MAIN_ID), "hidden");
 }
 
-function elemIsInParent(elem, parent) {
-    while (elem && elem !== document.body) {
-        if (elem === parent) {
-            return true;
-        }
-        elem = elem.parentElement;
-    }
-    return false;
-}
-
 function blurHandler(event, parentElem, hideCallback) {
-    if (!elemIsInParent(document.activeElement, parentElem) &&
-        !elemIsInParent(event.relatedTarget, parentElem)
+    if (!parentElem.contains(document.activeElement) &&
+        !parentElem.contains(event.relatedTarget)
     ) {
         hideCallback();
     }
@@ -1118,7 +1108,7 @@ function preLoadCss(cssUrl) {
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            if (!e.TOOLTIP_FORCE_VISIBLE && !elemIsInParent(ev.relatedTarget, e)) {
+            if (!e.TOOLTIP_FORCE_VISIBLE && !e.contains(ev.relatedTarget)) {
                 // See "Tooltip pointer leave gesture" below.
                 setTooltipHoverTimeout(e, false);
                 addClass(wrapper, "fade-out");
@@ -1178,10 +1168,10 @@ function preLoadCss(cssUrl) {
 
     function tooltipBlurHandler(event) {
         if (window.CURRENT_TOOLTIP_ELEMENT &&
-            !elemIsInParent(document.activeElement, window.CURRENT_TOOLTIP_ELEMENT) &&
-            !elemIsInParent(event.relatedTarget, window.CURRENT_TOOLTIP_ELEMENT) &&
-            !elemIsInParent(document.activeElement, window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE) &&
-            !elemIsInParent(event.relatedTarget, window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE)
+            !window.CURRENT_TOOLTIP_ELEMENT.contains(document.activeElement) &&
+            !window.CURRENT_TOOLTIP_ELEMENT.contains(event.relatedTarget) &&
+            !window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.contains(document.activeElement) &&
+            !window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.contains(event.relatedTarget)
         ) {
             // Work around a difference in the focus behaviour between Firefox, Chrome, and Safari.
             // When I click the button on an already-opened tooltip popover, Safari
@@ -1248,8 +1238,8 @@ function preLoadCss(cssUrl) {
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            if (!e.TOOLTIP_FORCE_VISIBLE &&
-                !elemIsInParent(ev.relatedTarget, window.CURRENT_TOOLTIP_ELEMENT)) {
+            if (!e.TOOLTIP_FORCE_VISIBLE && window.CURRENT_TOOLTIP_ELEMENT &&
+                !window.CURRENT_TOOLTIP_ELEMENT.contains(ev.relatedTarget)) {
                 // Tooltip pointer leave gesture:
                 //
                 // Designing a good hover microinteraction is a matter of guessing user
diff --git a/src/librustdoc/html/static/js/settings.js b/src/librustdoc/html/static/js/settings.js
index 63947789c54..70a2825265e 100644
--- a/src/librustdoc/html/static/js/settings.js
+++ b/src/librustdoc/html/static/js/settings.js
@@ -1,6 +1,6 @@
 // Local js definitions:
 /* global getSettingValue, updateLocalStorage, updateTheme */
-/* global addClass, removeClass, onEach, onEachLazy, blurHandler, elemIsInParent */
+/* global addClass, removeClass, onEach, onEachLazy, blurHandler */
 /* global MAIN_ID, getVar, getSettingsButton */
 
 "use strict";
@@ -232,7 +232,7 @@
         const settingsButton = getSettingsButton();
         const settingsMenu = document.getElementById("settings");
         settingsButton.onclick = event => {
-            if (elemIsInParent(event.target, settingsMenu)) {
+            if (settingsMenu.contains(event.target)) {
                 return;
             }
             event.preventDefault();
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 1e8ece7e114..6b536e97c43 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -1924,7 +1924,6 @@ fn resolution_failure(
                             Variant
                             | Field
                             | Closure
-                            | Coroutine
                             | AssocTy
                             | AssocConst
                             | AssocFn
diff --git a/triagebot.toml b/triagebot.toml
index c1482769852..593386288b4 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -626,7 +626,7 @@ cc = ["@nnethercote"]
 [assign]
 warn_non_default_branch = true
 contributing_url = "https://rustc-dev-guide.rust-lang.org/getting-started.html"
-users_on_vacation = ["jyn514", "WaffleLapkin", "oli-obk"]
+users_on_vacation = ["jyn514", "oli-obk"]
 
 [assign.adhoc_groups]
 compiler-team = [