[llvm] [InstCombine] Improve `(icmp pred (and X, Y), ...)` fold. (PR #66787)

[via llvm-commits]

goldsteinn wrote:

> I'm still trying to work out how best to create stacked PRs (especially when adding extra tests and want to show the diff) - everyone seems to have their own opinion on them right now :)

I don't really know either. If you know a better way than this I'm all ears.

https://github.com/llvm/llvm-project/pull/66787