If we are dealing with a pointer induction variable, isInductionPHI
gives back a step value of Stride / size of pointer. However, we might
be indexing with a legal type wider than the pointer width.
Handle this by inserting casts where appropriate instead of crashing.
This fixes PR23954.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240877 91177308-0d34-0410-b5e6-96231b3b80d8
8a8d8b3e59