Request for review (S)

[Keith McGuigan]

Bug Link: http://bugs.sun.com/view_bug.do?bug_id=6930553
Webrev: http://cr.openjdk.java.net/~kamg/6930553/webrev.01/

Summary:
For classfiles >= 51, check NameAndType_info constant pools entries more 
aggressively to make sure the signature is valid, even if the entry is 
not referenced by a Field, Method, or InterfaceMethod ref entry. This is 
required by the spec.

Thanks for any review!

--
- Keith