[llvm] [InstCombine] Make foldCmpLoadFromIndexedGlobal() GEP-type independent (PR #157089)

[Hongyu Chen via llvm-commits]

https://github.com/XChy commented:

The implementation LGTM.
The original logic for the state machines remains complicated. If possible, can you import some testcases from #67093?

https://github.com/llvm/llvm-project/pull/157089