RFR: 8024718: Metaspace performance counters and memory pools should report the same data

[Erik Helin]

Hi all,

this patch fixes some issues with memory pools and the performance
counter reporting slightly different numbers for metaspace. I've also
updated two jtreg tests as well as added a new one to test the change.

InputArguments.java in the testlibrary is updated as well.
InputArguments.contains now takes a prefix as a parameter instead of the
exact name of a flag. This makes it possible to check if a flag expecting
a value has been set. For example, -XX:MaxMetaspaceSize=100m can be
checked by running InputArguments.contains("-XX:MaxMetaspaceSize").

Webrev:
http://cr.openjdk.java.net/~ehelin/8024718/webrev.00/

Testing:
- JPRT
- hotspot/test/gc (including updated and new tests)

Thanks,
Erik