RFR:8139368:-javaagent and -Dcom.sun.management need to add to the initial set of modules to resolve

[Alexander Kulyakhtin]

Hi,

Could you, please, review this test-only change (adding a new test). 

CR: https://bugs.openjdk.java.net/browse/JDK-8139368 "-javaagent and -Dcom.sun.management need to add to the initial set of modules to resolve"
Webrev: http://cr.openjdk.java.net/~akulyakh/8139368_03/

Best regards,
Alexander