Rollup merge of rust-lang#63493 - sd234678:remove-unneeded-comment-from-src/libcore/hash, r=Centril

Remove unneeded comment in src/libcore/hash/mod.rs

Split out from larger PR rust-lang#63347 - other sections in there require further discussion.

r? @Centril

Author: Centril

src/libcore/hash/mod.rs

@@ -553,8 +553,6 @@ impl<H> PartialEq for BuildHasherDefault<H> {
 #[stable(since = "1.29.0", feature = "build_hasher_eq")]
 impl<H> Eq for BuildHasherDefault<H> {}
 
-//////////////////////////////////////////////////////////////////////////////
-
 mod impls {
     use crate::mem;
     use crate::slice;