RFR(XS): 8196124: [testbug] runtime/appcds/jigsaw/classpathtests/DummyClassesInBootClassPath.java passes despite of error

[Calvin Cheung]

bug: https://bugs.openjdk.java.net/browse/JDK-8196124

webrev: http://cr.openjdk.java.net/~ccheung/8196124/webrev.00/

Proposed changes:
- add "--add-modules java.activation" during dumping and run time since 
the java.activation module isn't defined by default;
- append the WhiteBox.jar to the -Xbootclasspath/a during dumping and 
create another archive for the test case which uses the WhiteBox API;
- add inspection of the run time result from the test case which uses 
the WhiteBox API;
- refactor DummyClassHelper.java; the classes in the classlist should be 
in the archive, the archived classes should be coming from the run time 
image, not from the jar file in the -cp.

Tested locally on linux-x64. Will test on other platforms after system 
maintenance is complete.

thanks,
Calvin