[llvm] [SCEV] Preserve flags in SCEVLoopGuardRewriter for add and mul. (PR #91472)

[Florian Hahn via llvm-commits]

fhahn wrote:

> Should this also handle AddRecExpr?

The default rewriter implementation already adds the flags https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h#L836 (not sure if that is safe in all cases)

https://github.com/llvm/llvm-project/pull/91472