[PATCH] D34918: [libc++] Refactoring __sync_* builtins; NFC

[Eric Fiselier via Phabricator via llvm-commits]

EricWF added a comment.

I'm not OK with adding a new header here. The problem is that `__refstring` requires using the new `<__atomic_support>` but `<__refstring>` shouldn't be a header anyway.

Could you please revert this till we figure out a better place for the builtins to live?


https://reviews.llvm.org/D34918