RFR: (S): JDK-8204308 : SA: serviceability/sa/TestInstanceKlassSize*.java fails when running in CDS mode

[Jini George]

Hello!

Requesting reviews for:
https://bugs.openjdk.java.net/browse/JDK-8204308
Webrev: http://cr.openjdk.java.net/~jgeorge/8204308/webrev.00/index.html

The proposed fix is to use longs instead of ints while computing the 
identity hash of klass symbols. It mimics the implementation of 
Symbol::identity_hash() in "src/hotspot/share/oops/symbol.hpp".

Thanks!
Jini.