RFR: 8364280: NMTCommittedVirtualMemoryTracker.test_committed_virtualmemory_region_vm fails with assertion "negative distance" [v2]

[Afshin Zafari]

> The VirtualMemoryTracker API uses a tree internally for tracking the memory regions and their states/info. This tree should not be changed when looking for some regions. If not synch'ed, the nodes in the tree may change meanwhile and the retrieved info are not as expected. The unit test in this PR did not synch these looking up with VMT. The corresponding lock is used to address the problem.
> 
> Tests:
> local: linux-x64-debug NMTGtests
> mach5: tiers 1-5, {macosx-aarch64, linux-x64, windows-x64} x {debug, release}

Afshin Zafari has updated the pull request incrementally with one additional commit since the last revision:

  space added

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26689/files
  - new: https://git.openjdk.org/jdk/pull/26689/files/829cce44..43a0a591

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26689&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26689&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/26689.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26689/head:pull/26689

PR: https://git.openjdk.org/jdk/pull/26689