Integrate LLVM at llvm/llvm-project@a8fbd1157deb
Integrate LLVM at llvm/llvm-project@a8fbd1157deb

Updates LLVM usage to match
[a8fbd1157deb](https://github.com/llvm/llvm-project/commit/a8fbd1157deb)

PiperOrigin-RevId: 479795396

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