[llvm] [DA] Widening SCEV expressions in strong SIV test to prevent overflow (PR #164704)

[Ryotaro Kasuga via llvm-commits]

kasuga-fj wrote:

I'm okay if you have some real world examples (but I'm not entirely sure why wider type is useful even though we don't know the bounds of symbolic values).

https://github.com/llvm/llvm-project/pull/164704