Integrate LLVM at llvm/llvm-project@4e8b2ac7c019
Integrate LLVM at llvm/llvm-project@4e8b2ac7c019

Updates LLVM usage to match
[4e8b2ac7c019](https://github.com/llvm/llvm-project/commit/4e8b2ac7c019)

PiperOrigin-RevId: 449977726

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