Request for review 8000725: NPG: method_holder() and pool_holder() and _pool_holder field should be InstanceKlass

[harold seigel]

Please review the following changes.

Summary: Change the function return type of method_holder(), 
field_holder(), and pool_holder() to InstanceKlass.  Also, change the 
type of field _pool_holder to InstanceKlass.  These changes enabled the 
removal of lots of InstanceKlass::cast() calls from the code.

This webrev has a lot of files but most of the changes are small.

Open webrev at http://cr.openjdk.java.net/~coleenp/bug_8000725 
<http://cr.openjdk.java.net/%7Ecoleenp/bug_8000725>

Bug link at http://bugs.sun.com/view_bug.do?bug_id=8000725

The changes were tested with JPRT, JCK, and other tests including ones 
for sa-jdi.

Thanks, Harold