[llvm] [InstCombine] Add reverse of ((X << nuw Z) sub nuw Y) >>u exact Z --> X sub nuw (Y >>u exact Z) (PR #91386)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

@AtariDreams The implementation looks OK to me. Please file another PR to reland this.

BTW, one of my friends from ms-stl told me you always use force-pushing to update your PR: https://github.com/microsoft/STL/pull/4140#issuecomment-1802757830. It is not a good practice :(




https://github.com/llvm/llvm-project/pull/91386