Improve root set used by hat

[Alan Bateman]

A. Sundararajan wrote:
> I agree. Static fields of classes loaded by non-bootstrap loaders 
> should not be part of root set.
>
> PS. I am not sure  if this is a bug with hat or with heap dumpers (the 
> hotspot built-in dumper and SA's dumper). I don't remember how "roots" 
> is filled. May be, these static fields should not be flagged as roots?
>
> -Sundar
At least for the built-in heap dumper, static fields aren't generated as 
roots (instead it's system classes and temporary placeholders in the 
dictionary that are generated to the dump as "sticky classes", to use a 
HPROF term). So I suspect this is more likely to be a jhat issue.

-Alan.