[10] RFR (XS): 8180366: [TESTBUG] gc/g1/humongousObjects/TestHumongousClassLoader should not be run with class unloading disabled

[Muthusamy Chinnathambi]

Hi,

Please review this trivial change for the fix of bug 'JDK-8180366 [TESTBUG] gc/g1/humongousObjects/TestHumongousClassLoader should not be run with class unloading disabled'

Summary:
This testcase(TestHumongousClassLoader.java) checks that unreachable classes and unreachable humongous class loader are unloaded after GC.  Hence we need to have class unloading enabled for the correctness of the test. The fix is to prohibit execution of the test if class unloading is disabled.

jdk10 bug: https://bugs.openjdk.java.net/browse/JDK-8180366
webrev link: http://cr.openjdk.java.net/~shshahma/Muthu/8180366/webrev.00/

Testing: I have manually confirmed that jtreg will no longer run the test if -XX:-ClassUnloading is used.

Regards,
Muthusamy C