RFR: (S): JDK-8213323: sa/TestJmapCoreMetaspace.java and sa/TestJmapCore.java fail with ZGC

[Jini George]

Hello!

Requesting reviews for a small change for disabling the testing of 
TestJmapCoreMetaspace.java and TestJmapCore.java with ZGC. The change 
also includes skipping of creating the heapdump file with jmap if the GC 
being used is ZGC.

Webrev: http://cr.openjdk.java.net/~jgeorge/8213323/webrev.00/
Bug ID: https://bugs.openjdk.java.net/browse/JDK-8213323

Thanks,
Jini.