<Swing Dev> RFR: JDK-8076468 : Update jtreg jdk_desktop tests to take into account the new modular architecture

[Alexander Kulyakhtin]

Hi,

Could you, please, review the changes below:

Webrev: http://cr.openjdk.java.net/~yan/8076468/webrev.00
CR : Change jtreg jdk_desktop tests to take into account the new modular architecture

This fix adds @modules keywords to the jtreg jdk_desktop tests as needed so the tests can access the necessary API as well as can be successfully found in tests selections when the new modular architecture is in place.

The fix is similar to what have already been done for hotspot in https://bugs.openjdk.java.net/browse/JDK-8075586

Best regards,
Alexander