The class `ClassLoaderData` has a field `_claim` to avoid applying oop closure more than once and the method `ClassLoaderData::oops_do` can check if the CLD had been claimed. It is good to use them to process the class loader data graph in parallel.

The parallel full gc has already used them in `MarkFromRootsTask::work` and `PSAdjustTask::work`. So I want to use it in young gc.