[llvm] [InstCombine] Update the `select` operand when the `cond` is `trunc` and has the `nuw` or `nsw` property. (PR #105914)

[via llvm-commits]

c8ef wrote:

Would it be better to place this transformation at https://github.com/llvm/llvm-project/blob/99b85cae628c1cc5641944290712cd84ccf1f6c8/llvm/lib/Analysis/InstructionSimplify.cpp#L4812? If yes, I'd like to relocate the implementation there.

https://github.com/llvm/llvm-project/pull/105914