Integrate LLVM at llvm/llvm-project@1a729bce8617
Integrate LLVM at llvm/llvm-project@1a729bce8617

Updates LLVM usage to match
[1a729bce8617](https://github.com/llvm/llvm-project/commit/1a729bce8617)

PiperOrigin-RevId: 452820639

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