// If the current task is a worker, save it on the spare_workers
// list of this Capability. A worker can mark itself as stopped,
// in which case it is not replaced on the spare_worker queue.
// This happens when the system is shutting down (see
// Schedule.c:workerStart()).
// If the current task is a worker, save it on the spare_workers
// list of this Capability. A worker can mark itself as stopped,
// in which case it is not replaced on the spare_worker queue.
// This happens when the system is shutting down (see
// Schedule.c:workerStart()).