dispatch_queue_create(3) on macOS

The text 50e8fc29c1fb, as macOS 10.12.6, macOS 10.12.5, macOS 10.12.4, macOS 10.12.3, macOS 10.12.2, macOS 10.12.1, macOS 10.12 shipped it.

where blocks are scheduled for execution

dispatch_queue_create(3) on macOS now