[llvm] [SCEVExpander] Clear flags when reusing GEP (PR #109293)

[Florian Hahn via llvm-commits]

https://github.com/fhahn approved this pull request.

LGTM, thanks!

It might be good to add a dedicated test for clearing the flags, rather than relying on AMDGPU/ARM LSR tests.

https://github.com/llvm/llvm-project/pull/109293