Revert "Using the unbounded queue in the queue_impl."

This reverts commit 125918f0df2f06f9b782c11dab096d8953cc1c02.
Removing gc.
Revert "Removing (redundant) second usleep in runnable dequeue."

This reverts commit 375ae5f9b689dece3a50d20c910e7beb1dcb3622.
Improve threadring more.
Optimizing threadring, eliminates literal token.
Adding experimental lock_sync to priv queue.