[InstCombine] reduce icmp_eq0-of-and-of-select-of-constants
This is the most basic patch to handle fixing issue #57666.
D133919 proposes to handle much more than this in a single patch,
but I've used 10 regression tests just to make sure this part is
doing what I expected and nothing more, and it already shows even
more potential TODO items.
The more general proofs from D133919 are correct, but I want to
enable this in smaller steps to reduce risk:
https://alive2.llvm.org/ce/z/RrVEyX
Differential Revision: https://reviews.llvm.org/D142847