Integrate LLVM at llvm/llvm-project@b540ee540266
Integrate LLVM at llvm/llvm-project@b540ee540266

Updates LLVM usage to match
[b540ee540266](https://github.com/llvm/llvm-project/commit/b540ee540266)

PiperOrigin-RevId: 446479075

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