Integrate LLVM at llvm/llvm-project@3c696a212ba4
Integrate LLVM at llvm/llvm-project@3c696a212ba4

Updates LLVM usage to match
[3c696a212ba4](https://github.com/llvm/llvm-project/commit/3c696a212ba4)

PiperOrigin-RevId: 343828493

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