[llvm] [InstCombine] Simplify compare abs(X) and X. (PR #76385)

[Nikita Popov via llvm-commits]

nikic wrote:

Please rebase over https://github.com/llvm/llvm-project/commit/9d5b0965c43b4e8b3f21c106fe829391b1382277 and move the fold into foldICmpCommutative().

https://github.com/llvm/llvm-project/pull/76385