[llvm] [ValueTracking] Expand cmpExcludesZero to optionally work with non-constant RHS (PR #69364)

[via llvm-commits]

goldsteinn wrote:

> Could you please provide the original motivating case for this? I think this goes beyond what is reasonable to handle in ValueTracking, and it would be best to handle your use case via LVI+CVP instead, if this is possible.

No strong motivating force. Guess the thinking was this is still basically a cheap check:
https://llvm-compile-time-tracker.com/compare.php?from=0ec39fb48e9dc4aad5f20bc50d44947ac004dd34&to=9031c8347dd041a4f34d8499d9e842ca9c33fd27&stat=instructions:u
And just improves coverage.
Can try adding to LVI, however.

https://github.com/llvm/llvm-project/pull/69364