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

[Ehsan Amiri via llvm-commits]

amehsan wrote:

> But isn't that isKnownPredicate always going to fail in the case where the multiply may overflow?

Right, when overflow for the product is a possibility that will work. Previously we thought for some simple loops, the product may overflow and we can prevent it.

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