[llvm-branch-commits] [clang] [release/18.x][COFF][Aarch64] Add _InterlockedAdd64 intrinsic (#81849) (PR #89951)

[Eli Friedman via llvm-branch-commits]

efriedma-quic wrote:

I think BuiltinsAArch64.def is part of clang's ABI, so changing it violates the backport rules.

Otherwise, I'd be inclined to accept; it's kind of late to request, but it's low risk.

https://github.com/llvm/llvm-project/pull/89951