Code review request: JDK-8005048,NMT: #loaded classes needs to just show the # defined classes

[Zhengyu Gu]

Current NMT implementation reports number of loaded classes at query 
time, but number of defined classes is what is expected.

This changset reflects two major changes:

1. It counts number of defined classes vs. number of loaded classes
2. It counts number of defined classes for each generation, vs. counts 
at query time. In this way, the number of defined classes that NMT 
reports, should match the corresponding class metadata data. As the 
result, the data should be more accurate.


Webrev: http://cr.openjdk.java.net/~zgu/8005048/webrev.00/


Thanks,

-Zhengyu