[InstCombine] Perform "eq of parts" fold with logical ops

The pattern matched here is too complex for the general logical
and/or to bitwise and/or conversion to trigger. However, the
fold is poison-safe, so match it with a select root as well:

https://alive2.llvm.org/ce/z/vNzzSg
https://alive2.llvm.org/ce/z/Beyumt