[TargetLowering] Add ISD::AND handling to SimplifyDemandedVectorElts

If either of the operand elements are zero then we know the result element is going to be zero (even if the other element is undef).

Differential Revision: https://reviews.llvm.org/D55558

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348926 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed