Auto merge of #119892 - joboet:libs_use_assert_unchecked, r=Nilstrieb,cuviper

Use `assert_unchecked` instead of `assume` intrinsic in the standard library

Now that a public wrapper for the `assume` intrinsic exists, we can use it in the standard library.

CC #119131

library/std/src/lib.rs

@@ -325,6 +325,7 @@
 #![feature(float_next_up_down)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(hashmap_internals)]
+#![feature(hint_assert_unchecked)]
 #![feature(ip)]
 #![feature(maybe_uninit_slice)]
 #![feature(maybe_uninit_uninit_array)]