[clang] [InstCombine] Canonicalize constant GEPs to i8 source element type (PR #68882)

[Nikita Popov via cfe-commits]

https://github.com/nikic commented:

I looked through the test diffs, and it seems like the only substantial regressions are all related to the indexed compare fold, which should be made type-independent.

https://github.com/llvm/llvm-project/pull/68882