[PATCH] D24153: Add bunch of _Interlocked builtins

[David Majnemer via cfe-commits]

majnemer added a comment.

In https://reviews.llvm.org/D24153#535992, @rnk wrote:

> Looks good to me. David, do you remember any subtleties here? I seem to recall there were some bugs in our intrin.h implementations, or inconsistencies between us and MSVC.


I can't seem to recall anything major.  Our `_ReadBarrier` and `_WriteBarrier` simply map to `_ReadWriteBarrier`.  Our `__faststorefence` is just a normal fence instead of an interlocked operation.


https://reviews.llvm.org/D24153