[InstCombine] use m_APInt to allow icmp eq (op X, Y), C folds for splat constant vectors

I'm removing a misplaced pair of more specific folds from InstCombine in this patch as well,
so we know where those folds are happening in InstSimplify.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277738 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed