[llvm] [InstCombine] lshr (mul (X, 2^N + 1)), N -> add (X, lshr(X, N)) (PR #90295)

[Craig Topper via llvm-commits]

topperc wrote:

The `tgt` function in your Alive2 proof has a dead instruction in it that is distracting to reviewing the proof.

https://github.com/llvm/llvm-project/pull/90295