Rollup merge of rust-lang#115477 - kellerkindt:stabilized_int_impl, r=dtolnay

Stabilize the `Saturating` type

Closes rust-lang#87920
Closes rust-lang#92354

Stabilization report rust-lang#87920 (comment)
FCP rust-lang#87920 (comment)

Author: Dylan-DPC

tests/ui/arithmetic_side_effects.rs

@@ -10,7 +10,7 @@
     arithmetic_overflow,
     unconditional_panic
 )]
-#![feature(const_mut_refs, inline_const, saturating_int_impl)]
+#![feature(const_mut_refs, inline_const)]
 #![warn(clippy::arithmetic_side_effects)]
 
 extern crate proc_macro_derive;