Use allow_internal_unstable and add unstable reason

compiler/rustc_ast/src/lib.rs

@@ -15,7 +15,6 @@
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
-#![feature(spec_option_partial_eq)]
 #![feature(negative_impls)]
 #![feature(slice_internals)]
 #![feature(stmt_expr_attributes)]

compiler/rustc_borrowck/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
-#![feature(spec_option_partial_eq)]
 #![feature(stmt_expr_attributes)]
 #![feature(trusted_step)]
 #![feature(try_blocks)]

compiler/rustc_data_structures/src/lib.rs

@@ -13,7 +13,6 @@
 #![feature(cell_leak)]
 #![feature(control_flow_enum)]
 #![feature(extend_one)]
-#![feature(spec_option_partial_eq)]
 #![feature(hash_raw_entry)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(maybe_uninit_uninit_array)]

compiler/rustc_hir/src/lib.rs

@@ -9,7 +9,6 @@
 #![feature(never_type)]
 #![feature(rustc_attrs)]
 #![feature(variant_count)]
-#![feature(spec_option_partial_eq)]
 #![recursion_limit = "256"]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

compiler/rustc_hir_analysis/src/lib.rs

@@ -65,7 +65,6 @@
 #![feature(is_sorted)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
-#![feature(spec_option_partial_eq)]
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(once_cell)]

compiler/rustc_hir_typeck/src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(try_blocks)]
 #![feature(never_type)]
 #![feature(min_specialization)]
-#![feature(spec_option_partial_eq)]
 #![feature(control_flow_enum)]
 #![feature(drain_filter)]
 #![allow(rustc::potential_query_instability)]

compiler/rustc_index/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(new_uninit)]
 #![feature(step_trait)]
 #![feature(stmt_expr_attributes)]
-#![feature(spec_option_partial_eq)]
 #![feature(test)]
 
 pub mod bit_set;

compiler/rustc_infer/src/lib.rs

@@ -19,7 +19,6 @@
 #![feature(extend_one)]
 #![feature(let_chains)]
 #![feature(if_let_guard)]
-#![feature(spec_option_partial_eq)]
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(try_blocks)]

compiler/rustc_lint/src/lib.rs

@@ -34,7 +34,6 @@
 #![feature(iter_intersperse)]
 #![feature(iter_order_by)]
 #![feature(let_chains)]
-#![feature(spec_option_partial_eq)]
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![recursion_limit = "256"]

compiler/rustc_macros/src/lib.rs

@@ -47,7 +47,7 @@ pub fn symbols(input: TokenStream) -> TokenStream {
 /// `u32::MAX`. You can also customize things like the `Debug` impl,
 /// what traits are derived, and so forth via the macro.
 #[proc_macro]
-#[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
+#[allow_internal_unstable(step_trait, rustc_attrs, trusted_step, spec_option_partial_eq)]
 pub fn newtype_index(input: TokenStream) -> TokenStream {
     newtype::newtype(input)
 }

compiler/rustc_middle/src/lib.rs

@@ -31,7 +31,6 @@
 #![feature(discriminant_kind)]
 #![feature(exhaustive_patterns)]
 #![feature(get_mut_unchecked)]
-#![feature(spec_option_partial_eq)]
 #![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(never_type)]

compiler/rustc_mir_build/src/lib.rs

@@ -7,7 +7,6 @@
 #![feature(control_flow_enum)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
-#![feature(spec_option_partial_eq)]
 #![feature(min_specialization)]
 #![feature(once_cell)]
 #![recursion_limit = "256"]

compiler/rustc_mir_dataflow/src/lib.rs

@@ -4,7 +4,6 @@
 #![feature(min_specialization)]
 #![feature(once_cell)]
 #![feature(stmt_expr_attributes)]
-#![feature(spec_option_partial_eq)]
 #![feature(trusted_step)]
 #![recursion_limit = "256"]
 #![deny(rustc::untranslatable_diagnostic)]

compiler/rustc_mir_transform/src/lib.rs

@@ -7,7 +7,6 @@
 #![feature(once_cell)]
 #![feature(option_get_or_insert_default)]
 #![feature(trusted_step)]
-#![feature(spec_option_partial_eq)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
 #![feature(if_let_guard)]

compiler/rustc_passes/src/lib.rs

@@ -11,7 +11,6 @@
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(map_try_insert)]
-#![feature(spec_option_partial_eq)]
 #![feature(min_specialization)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]

compiler/rustc_query_system/src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(hash_raw_entry)]
 #![feature(min_specialization)]
 #![feature(extern_types)]
-#![feature(spec_option_partial_eq)]
 #![allow(rustc::potential_query_instability)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

compiler/rustc_span/src/lib.rs

@@ -18,7 +18,6 @@
 #![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(min_specialization)]
-#![feature(spec_option_partial_eq)]
 #![feature(rustc_attrs)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

compiler/rustc_target/src/lib.rs

@@ -14,7 +14,6 @@
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
-#![feature(spec_option_partial_eq)]
 #![feature(step_trait)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

compiler/rustc_type_ir/src/lib.rs

@@ -1,7 +1,6 @@
 #![feature(fmt_helpers_for_derive)]
 #![feature(min_specialization)]
 #![feature(rustc_attrs)]
-#![feature(spec_option_partial_eq)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 

library/core/src/option.rs

@@ -2045,13 +2045,13 @@ fn eq(&self, other: &Self) -> bool {
     }
 }
 
-#[unstable(feature = "spec_option_partial_eq", issue = "none")]
+#[unstable(feature = "spec_option_partial_eq", issue = "none", reason = "exposed only for rustc")]
 #[doc(hidden)]
 pub trait SpecOptionPartialEq: Sized {
     fn eq(l: &Option<Self>, other: &Option<Self>) -> bool;
 }
 
-#[unstable(feature = "spec_option_partial_eq", issue = "none")]
+#[unstable(feature = "spec_option_partial_eq", issue = "none", reason = "exposed only for rustc")]
 impl<T: PartialEq> SpecOptionPartialEq for T {
     #[inline]
     default fn eq(l: &Option<T>, r: &Option<T>) -> bool {