RFR: 8073388: Get rid of the dependency from handles.hpp to klass.hpp

[Stefan Karlsson]

Hi,

Please review this patch to get rid of dependencies from handles.hpp to 
klass.hpp. This patch is extracted from a bigger patch to clean up some 
of our GC code dependencies in oop_iterate.

http://cr.openjdk.java.net/~stefank/8073388/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8073388

Thanks,
StefanK