[clang] [AMD-GPU] Fix smfmac builtin target (PR #193999)

[Jordan Fogel via cfe-commits]

FIM43-Redeye wrote:

Looks good -- `REQUIRES` is in, indent is 2-space, all 6 builtins covered. CI's re-running on Linux/AArch64/Windows after the new commit; assuming those come back green (the earlier AArch64 flake was unrelated), this is ready for reviewer attention.

Appreciate the iteration. If something good-first-issue-shaped comes up in ROCm/AMDGPU land that'd be useful for you, I'll ping you.


https://github.com/llvm/llvm-project/pull/193999