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

[Nikita Popov via llvm-commits]

nikic wrote:

But isn't that isKnownPredicate always going to fail in the case where the multiply may overflow? That means that the value is potentially larger than the original type, and AbsDelta fits within that type. Maybe I'm misunderstanding something here.

By the way, it should be possible to write a test for this using `-da-enable-dependence-test`, to test the fix for SDIV even if RDIV is still buggy.

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