hg: zgc/zgc: ZGC: UPSTREAM: 8196217: NMT: add_committed_regions doesn't merge succeeding regions

[stefan.karlsson at oracle.com]

Changeset: 7ce28087d321
Author:    stefank
Date:      2018-01-29 18:53 +0100
URL:       http://hg.openjdk.java.net/zgc/zgc/rev/7ce28087d321

ZGC: UPSTREAM: 8196217: NMT: add_committed_regions doesn't merge succeeding regions

! src/hotspot/share/services/virtualMemoryTracker.cpp
+ test/hotspot/jtreg/runtime/NMT/VirtualAllocCommitMerge.java