[InstCombine] use m_APInt to allow icmp (binop X, Y), C folds with constant splat vectors

This removes the restriction for the icmp constant, but as noted by the FIXME comments, 
we still need to change individual checks for binop operand constants.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277629 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed