[llvm] [InstCombine] Avoid folding `select(umin(X, Y), X)` with min/max values in false arm (PR #143020)

[Konstantin Bogdanov via llvm-commits]

thevar1able wrote:

Thank you!

I see 20.1.7 was released just a couple hours before merge; is 20.1.8 expected, or should I expect this to land in 21?

https://github.com/llvm/llvm-project/pull/143020