[llvm] [VPlan] Allow folding not (cmp eq) -> icmp ne with other select users (PR #154497)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon approved this pull request.

I think that, given the current state of the code, this is the best we can do for now. LGTM, thanks!

https://github.com/llvm/llvm-project/pull/154497