test: remove unneeded tests

AsyncWrap will be going through many changes, and the old API will no
longer be used. So remove those tests that will no longer be useful.
They may be added back later using the new API, once fully implemented.

PR-URL: nodejs#12892
Ref: nodejs#11883
Ref: nodejs#8531
Reviewed-By: Andreas Madsen <amwebdk@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

Author: trevnorris