[clang] [lld] [llvm] [LTO] enable `ObjCARCContractPass` only on optimized build (PR #101114)

[Nikita Popov via llvm-commits]

nikic wrote:

The pipeline test changes here still look problematic. Can you make the ObjCARCContract pass preserve the DT?

https://github.com/llvm/llvm-project/pull/101114