[InstCombine] change insertRangeTest() to use APInt instead of Constant; NFCI

This is prep work before changing the callers to also use APInt which will
allow folds for splat vectors. Currently, the callers have ConstantInt
guards in place, so no functional change intended with this commit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280282 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed