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

[Nuri Amari via cfe-commits]

NuriAmari wrote:

> Shouldn't this be added to the LTO code generator? In `libLTO` (used by Apple's linker) it is added here `llvm/lib/LTO/ThinLTOCodeGenerator.cpp`

Presumably because the pass is likely not useful unless targeting MachO, LLD does this via configuration hook: https://reviews.llvm.org/D94547. I'm already doing it unconditionally, so what do you think about adding the pass here: https://github.com/llvm/llvm-project/blob/main/llvm/lib/LTO/LTOBackend.cpp#L417, and deleting this: https://github.com/llvm/llvm-project/blob/main/lld/MachO/LTO.cpp#L51-L53 ?

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