Integrate LLVM at llvm/llvm-project@c531171d9957
Integrate LLVM at llvm/llvm-project@c531171d9957

Updates LLVM usage to match
[c531171d9957](https://github.com/llvm/llvm-project/commit/c531171d9957)

PiperOrigin-RevId: 438319307

google-research/structured-additive-IR,google-research/structured-additive-IR