RFR: JDK-8076468: Add @modules to jtreg jdk_desktop tests to take into account the new modular architecture

[Alexander Kulyakhtin]

Hi,

Could you, please, review the following tests-only changes to the test files 
from the jdk9/client repository

http://cr.openjdk.java.net/~akulyakh/8076468/webrev.02/index.html

The changes add @modules to the tests to make it possible to run the tests with 
jake. 

Best regards,
Alexander