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

[Florian Hahn via cfe-commits]

fhahn 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`

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