Remove redundant feature flags

Folyd · Folyd · commit 5951055f6627 · 2021-01-30T14:18:38.000+08:00
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
@@ -165,8 +165,6 @@
 #![feature(no_niche)] // rust-lang/rust#68303
 #![feature(unsafe_block_in_unsafe_fn)]
 #![feature(int_error_matching)]
-#![feature(iter_at_least)]
-#![feature(iter_at_most)]
 #![deny(unsafe_op_in_unsafe_fn)]
 
 #[prelude_import]
