[llvm] [GVNSink] Fix incorrect codegen with respect to GEPs #85333 (PR #88440)

[Nikita Popov via llvm-commits]

nikic wrote:

This is exactly the test non-determinism issue I've mentioned before. I think at this point we cannot make any fixes to GVNSink until the non-determinism issue is fixed and we can actually write tests for this pass.

https://github.com/llvm/llvm-project/pull/88440