Integrate LLVM at llvm/llvm-project@a4bf361454c4
Integrate LLVM at llvm/llvm-project@a4bf361454c4

Updates LLVM usage to match
[a4bf361454c4](https://github.com/llvm/llvm-project/commit/a4bf361454c4)

PiperOrigin-RevId: 454534149

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