[InstCombine] Handle undefs in and of icmp eq zero fold

For the scalar/splat case, this fold is subsumed by
foldLogOpOfMaskedICmps(). However, the conjugated fold for "or"
also supports splats with undef. Make both code paths consistent
by using m_ZeroInt() for the "and" implementation as well.

https://alive2.llvm.org/ce/z/tN63cu
https://alive2.llvm.org/ce/z/ufB_Ue