dispatch_source_create(3) on macOS

The text ca104a9041c5, as Mac OS X 10.8.5, Mac OS X 10.8.4, Mac OS X 10.8.3, Mac OS X 10.8.2, Mac OS X 10.8.1, Mac OS X 10.8 shipped it.

dispatch event sources

dispatch_source_create(3) on macOS now