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

[Kyungwoo Lee via cfe-commits]

https://github.com/kyulee-com approved this pull request.

I think `ObjCARCContractPass` is ideally suited for MachO rather than ELF. There might be a consideration to add it conditionally, however, this could be excessive. Like the (full)LTO pass -- https://github.com/llvm/llvm-project/blob/main/llvm/lib/LTO/LTOCodeGenerator.cpp#L141, I think this approach results in a no-op for ELF and it should be okay.

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