`test-dgram-*` test failures on macOS

[kfarnung]

• Version: master
• Platform: macOS
• Subsystem: dgram

I'm seeing consistent timeout failures for a few of the test-dgram-* tests:

not ok 401 parallel/test-dgram-send-empty-array
not ok 402 parallel/test-dgram-send-empty-buffer
not ok 563 parallel/test-dgram-send-empty-packet

https://ci.nodejs.org/job/chakracore-test-osx/415/nodes=osx1010/