RFR (XS) 8209384: ProblemList stressHierarchy metaspace tests

[coleen.phillimore at oracle.com]

Summary: These try to trigger GC by filling metaspace which seems to be 
not working.

open webrev at http://cr.openjdk.java.net/~coleenp/8209384.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8209384

Tested by not running the tests with make run-test.

Thanks,
Coleen