[llvm] [CodeGenPrepare] Don't sink icmp eq (and X, mask), 0 into return blocks (PR #200460)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon requested changes to this pull request.

Fix the commit sequence - the first commit should show the tests WITH CURRENT TRUNK codegen - the later commits should then show the tests' codegen changes

https://github.com/llvm/llvm-project/pull/200460