[llvm] [SeperateConstOffsetFromGEP] Handle `or disjoint` flags (PR #76997)

[Krzysztof Drewniak via llvm-commits]

krzysz00 wrote:

Looks like removing the NoBitsInCommon checks breaks an existing test - would it make more sense to go annotate said test with `disjoint` or to keep the check?

https://github.com/llvm/llvm-project/pull/76997