Integrate LLVM at llvm/llvm-project@311dd55c9eb9
Integrate LLVM at llvm/llvm-project@311dd55c9eb9

Updates LLVM usage to match
[311dd55c9eb9](https://github.com/llvm/llvm-project/commit/311dd55c9eb9)

PiperOrigin-RevId: 414402181

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