Remove unnecessary feature gates

Author: jhpratt

compiler/rustc_codegen_ssa/src/lib.rs

@@ -2,7 +2,6 @@
 #![feature(associated_type_bounds)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
-#![feature(int_roundings)]
 #![feature(let_chains)]
 #![feature(negative_impls)]
 #![feature(never_type)]

library/std/src/lib.rs

@@ -293,7 +293,6 @@
 #![feature(float_next_up_down)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(hashmap_internals)]
-#![feature(int_roundings)]
 #![feature(ip)]
 #![feature(ip_in_core)]
 #![feature(maybe_uninit_slice)]