RFR(XXS) 8186748: NMT: memTracker::record_virtual_memory_reserve_and_commit() does not tag the memory as committed

[Zhengyu Gu]

Please review this one line change to fix missing tag of committed 
memory region.

The bug results NMT to report "Shared class space" as reserved, but not 
committed region.


bug:    https://bugs.openjdk.java.net/browse/JDK-8186748
Webrev: http://cr.openjdk.java.net/~zgu/8186748/webrev.00/



Before:

- Shared class space (reserved=16904KB, committed=0KB)
                             (mmap: reserved=16904KB, committed=0KB)

After:

-        Shared class space (reserved=16832KB, committed=16832KB)
                             (mmap: reserved=16832KB, committed=16832KB)


Thanks,

-Zhengyu