Make intrinsics::assume const stable

Closes rust-lang#76972
Blocks rust-lang#119452

Approved in rust-lang#119452 (comment)

Author: AngelicosPhosphoros

library/core/src/intrinsics.rs

@@ -947,7 +947,7 @@ extern "rust-intrinsic" {
     /// own, or if it does not enable any significant optimizations.
     ///
     /// This intrinsic does not have a stable counterpart.
-    #[rustc_const_unstable(feature = "const_assume", issue = "76972")]
+    #[rustc_const_stable(feature = "const_assume", since = "CURRENT_RUSTC_VERSION")]
     #[rustc_nounwind]
     pub fn assume(b: bool);
 

library/core/src/lib.rs

@@ -119,7 +119,6 @@
 #![feature(const_arguments_as_str)]
 #![feature(const_array_from_ref)]
 #![feature(const_array_into_iter_constructors)]
-#![feature(const_assume)]
 #![feature(const_bigint_helper_methods)]
 #![feature(const_black_box)]
 #![feature(const_caller_location)]

library/core/tests/lib.rs

@@ -7,7 +7,6 @@
 #![feature(bigint_helper_methods)]
 #![feature(cell_update)]
 #![feature(const_align_offset)]
-#![feature(const_assume)]
 #![feature(const_align_of_val_raw)]
 #![feature(const_black_box)]
 #![feature(const_caller_location)]