[llvm] [SCEV] Add SafeWrap flag to AddRecs (PR #118483)

[Júlio De Bastiani via llvm-commits]

OtherRandomUser wrote:

> Do I understand correctly that the "safe-wrap" flag does not actually carry any operational semantics, and is just a marker to disable nowrap predication?

That is correct. In the snippet I shared above we are interested in the and operation `int ind = i & 0x7f;`, which is modeled as `(zext i7 {0,+,1}<sw><%for.body> to i32)`. The problem we were running into is that during the creation of the scev checks for vectorization `SCEVPredicateRewriter` was removing the zext expression in favor of a no wrap predicate. This patch was made to solve that problem.

https://github.com/llvm/llvm-project/pull/118483