remove some things that do not need to be

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -960,7 +960,7 @@ fn visit_expr(&mut self, ex: &'hir hir::Expr<'hir>) {
                         sm.span_to_diagnostic_string(span)
                     }
                 };
-                let mut spans: MultiSpan = spans.clone().into();
+                let mut spans: MultiSpan = spans.into();
                 // Point at all the `continue`s and explicit `break`s in the relevant loops.
                 for (desc, elements) in [
                     ("`break` exits", &finder.found_breaks),

compiler/rustc_builtin_macros/src/source_util.rs

@@ -333,10 +333,8 @@ fn find_path_suggestion(
     .flatten()
     .take(4);
 
-    for new_path in root_absolute.chain(add).chain(remove) {
-        if source_map.file_exists(&base_dir.join(&new_path)) {
-            return Some(new_path);
-        }
-    }
-    None
+    root_absolute
+        .chain(add)
+        .chain(remove)
+        .find(|new_path| source_map.file_exists(&base_dir.join(&new_path)))
 }

compiler/rustc_feature/src/builtin_attrs.rs

@@ -1082,7 +1082,7 @@ pub fn is_builtin_attr_name(name: Symbol) -> bool {
 /// This means it can be used cross crate.
 pub fn encode_cross_crate(name: Symbol) -> bool {
     if let Some(attr) = BUILTIN_ATTRIBUTE_MAP.get(&name) {
-        if attr.encode_cross_crate == EncodeCrossCrate::Yes { true } else { false }
+        attr.encode_cross_crate == EncodeCrossCrate::Yes
     } else {
         true
     }

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -1134,7 +1134,7 @@ enum ProhibitGenericsArg {
         for (what, span) in types_and_spans {
             err.span_label(span, format!("not allowed on {what}"));
         }
-        generics_args_err_extend(self.tcx(), segments.clone(), &mut err, err_extend);
+        generics_args_err_extend(self.tcx(), segments, &mut err, err_extend);
         let reported = err.emit();
         self.set_tainted_by_errors(reported);
         reported

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -2009,7 +2009,7 @@ fn encode_impls(&mut self) -> LazyArray<TraitImpls> {
                     .push((id.owner_id.def_id.local_def_index, simplified_self_ty));
 
                 let trait_def = tcx.trait_def(trait_ref.def_id);
-                if let Some(mut an) = trait_def.ancestors(tcx, def_id).ok() {
+                if let Ok(mut an) = trait_def.ancestors(tcx, def_id) {
                     if let Some(specialization_graph::Node::Impl(parent)) = an.nth(1) {
                         self.tables.impl_parent.set_some(def_id.index, parent.into());
                     }

compiler/rustc_parse/src/parser/expr.rs

@@ -3585,8 +3585,7 @@ pub(super) fn parse_struct_fields(
 
             match self.expect_one_of(&[token::Comma], &[token::CloseDelim(close_delim)]) {
                 Ok(_) => {
-                    if let Some(f) =
-                        parsed_field.or_else(|guar| field_ident(self, guar).ok_or(guar)).ok()
+                    if let Ok(f) = parsed_field.or_else(|guar| field_ident(self, guar).ok_or(guar))
                     {
                         // Only include the field if there's no parse error for the field name.
                         fields.push(f);

compiler/rustc_query_system/src/dep_graph/serialized.rs

@@ -541,12 +541,7 @@ fn encode_node(
         record_graph: &Option<Lock<DepGraphQuery>>,
     ) -> DepNodeIndex {
         node.encode::<D>(&mut self.encoder);
-        self.record(
-            node.node,
-            node.edges.len(),
-            |_| node.edges[..].iter().copied().collect(),
-            record_graph,
-        )
+        self.record(node.node, node.edges.len(), |_| node.edges[..].to_vec(), record_graph)
     }
 
     /// Encodes a node that was promoted from the previous graph. It reads the information directly from