[LoopAccessAnalysis] Fix an integer overflow

We were inappropriately using 32-bit types to account for quantities
that can be far larger.

Fixed in PR28443.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274737 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed