Code review request: NMT: assertion failed: assert(rec->addr() + rec->size() <= cur->base()) failed: Can not overlap in memSnapshot.cpp

[Zhengyu Gu]

NMT did not allow overlapped commit on memory regions, which is 
incorrect. Committing overlapped memory regions should be allowed, as 
long as the regions are within a reserved region.

http://cr.openjdk.java.net/~zgu/8001591/webrev.00/

Thanks,

-Zhengyu