Rollup merge of rust-lang#94730 - msabansal:sabansal/b-atomic-mut-ptr, r=Dylan-DPC

Reverted atomic_mut_ptr feature removal causing compilation break

Fixes a regression introduced as part of rust-lang#94546

Std no longer compiles on nightly while using the following commnd:

export RUSTFLAGS='-C target-feature=+atomics,+bulk-memory'
cargo build --target wasm32-unknown-unknown -Z build-std=panic_abort,std

I can help add tests to avoid future breaks but i couldn't understand the test framework

Author: Dylan-DPC

library/std/src/lib.rs

@@ -231,6 +231,7 @@
 #![feature(assert_matches)]
 #![feature(associated_type_bounds)]
 #![feature(async_iterator)]
+#![feature(atomic_mut_ptr)]
 #![feature(bench_black_box)]
 #![feature(box_syntax)]
 #![feature(c_unwind)]