Integrate LLVM at llvm/llvm-project@c490f8feb71e
Integrate LLVM at llvm/llvm-project@c490f8feb71e

Updates LLVM usage to match
[c490f8feb71e](https://github.com/llvm/llvm-project/commit/c490f8feb71e)

PiperOrigin-RevId: 421298939

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