[llvm] [llvm] Use llvm::less_first and llvm::less_second (NFC) (PR #136272)

[Kazu Hirata via llvm-commits]

kazutakahirata wrote:

@vvereschaka

> Reverting to `std::sort` in `llvm/lib/Target/AMDGPU/AMDGPUIGroupLP.cpp` seems to fix the problems. I'll post a PR shortly.

I just posted https://github.com/llvm/llvm-project/pull/136615.



https://github.com/llvm/llvm-project/pull/136272