With JDK-8368124, it starts showing thread name. However, it has length constraints. Since `Shenandoah` is a long word, for control or regulator threads, we'd see something like `(Shenand..Thread) (Shenand..eads#0) `, so we lost ability to tell if which threads they are. I see the same in debug console - thread names got trimmed due to length constraints and couldn't tell if the thread is a control thread, worker thread or regulator thread.

Abbreviate the thread names when length constraints apply.