Rollup merge of rust-lang#66538 - dingelish:master, r=Centril

Remove compiler_builtins_lib feature from libstd

Test if we can close rust-lang#66368 by this patch.

Author: Centril

src/libstd/lib.rs

@@ -244,7 +244,6 @@
 #![feature(cfg_target_thread_local)]
 #![feature(char_error_internals)]
 #![feature(clamp)]
-#![feature(compiler_builtins_lib)]
 #![feature(concat_idents)]
 #![feature(const_cstr_unchecked)]
 #![feature(const_raw_ptr_deref)]