[clang] [llvm] [ConstantFold] Drop gep of gep fold entirely (PR #95126)

[via cfe-commits]

agozillon wrote:

Just landed the PR, so it should be good to land this PR now without causing issues with the flang+openmp+offload buildbot, however, if any other issues do arise, I am happy to look into them! But from testing this PR in conjunction with the one I just landed locally, it does seem like everything should be fine. 

https://github.com/llvm/llvm-project/pull/95126