[clang] [lld] [llvm] Run ObjCContractPass in Distributed Thin-LTO Pipeline (PR #92331)

[Steven Wu via llvm-commits]

cachemeifyoucan wrote:

> I couldn't find this check you're alluding to, so I added my own. If the check does exist, could you point me to it? If not, does mine look reasonable? Thanks.

I was answering from my memory, now I have to check. We have this function `ModuleHasARC` which is used in other ARC optimization passes. It used to be in arc-contract pass too but it seems to be dropped by https://reviews.llvm.org/D92808

It is a good idea to added it back. Maybe by reusing the same function after double check the context of the old patch. @ahatanaka might have idea if there is a reason to drop the guard.

https://github.com/llvm/llvm-project/pull/92331