Update src/libcore/sync/atomic.rs
Update src/libcore/sync/atomic.rs

Co-authored-by: Ralf Jung <9b466094ec991a03cb95c489c19c4d75635f0ae5@ralfj.de>
aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust