Method try_dequeue_bulk

deps/concurrentqueue/concurrentqueue.h:1210–1220

	// Never allocates. Thread-safe.
	template<typename It>
	size_t try_dequeue_bulk(It itemFirst, size_t max)
	{
		size_t count = 0;
		for (auto ptr = producerListTail.load(std::memory_order_acquire); ptr != nullptr; ptr = ptr->next_prod()) {
			count += ptr->dequeue_bulk(itemFirst, max - count);
			if (count == max) {
				break;
			}
		}
		return count;
	}
	
	// Attempts to dequeue several elements from the queue using an explicit consumer token.
	// Returns the number of items actually dequeued.