Integrate LLVM at llvm/llvm-project@6154c4115cd4
Integrate LLVM at llvm/llvm-project@6154c4115cd4

Updates LLVM usage to match
[6154c4115cd4](https://github.com/llvm/llvm-project/commit/6154c4115cd4)

PiperOrigin-RevId: 338262655

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