[llvm] [InstCombine] Add test for freeze of GEP with recurrence offset (NFC) (PR #145541)

[David Sherwood via llvm-commits]

https://github.com/david-arm approved this pull request.

LGTM! The formatting issue refers purely to a comment so that's fine with me.

https://github.com/llvm/llvm-project/pull/145541