RFR(XS) 8166155: Create tests for VM module option handling

[George Triantafillou]

Please review this change that adds test coverage for the new VM module 
option handling implemented in 
https://bugs.openjdk.java.net/browse/JDK-8157038.

JBS: https://bugs.openjdk.java.net/browse/JDK-8166155
webrev: http://cr.openjdk.java.net/~gtriantafill/8166155/webrev/ 
<http://cr.openjdk.java.net/%7Egtriantafill/8166155/webrev/>

Tested locally on Linux.

Thanks.

-George