Rollup merge of #97320 - usbalbin:stabilize_const_ptr_read, r=m-ou-se

Stabilize const_ptr_read

Stabilizes const_ptr_read, with tracking issue #80377

Author: matthiaskrgr

tests/fail/const-ub-checks.rs

@@ -1,4 +1,3 @@
-#![feature(const_ptr_read)]
 
 const UNALIGNED_READ: () = unsafe {
     let x = &[0u8; 4];