Code review request: CR 7181995 NMT ON: NMT assertion failure assert(cur_vm->is_uncommit_record() || cur_vm->is_deallocation_record

[Zhengyu Gu]

This is a pretty significant changes on how NMT deal with virtual memory 
records. The old logic processed virtual memory records based on memory 
address order, then sequence number, which was fault, since virtual 
memory operations do not have to base on the ranges' base addresses. The 
corrected logic is to process virtual memory records purely based on the 
sequence number.

CR: http://bugs.sun.com/view_bug.do?bug_id=7181995
Webrev: http://cr.openjdk.java.net/~zgu/7181995/webrev.00/

The changes passed following tests:
   - JPRT tests
   - vm quick tests
   - Parallel classloading tests
   - nsk stress tests
   - jck60 stress tests
   - quick jdi tests
   - quick jvmti tests

Thanks,

-Zhengyu