RFR: 8359959: Test runtime/NMT/VirtualAllocTestType.java failed: '\\[0x[0]*7f7dc4043000 - 0x[0]*7f7dc4083000\\] reserved 256KB for Test' missing from stdout/stderr

[Afshin Zafari]

The test expects that two disjunct regions are reserved but checked it incompletely.
It is fixed by reserving a region with triple required size and then released the middle part.

 Since it (reserving two regions that become adjacent) is not happening always, the test failed occasionally at different tiers.

Tested local linux-x64-debug.

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Commit messages:
 - 8359959: Test runtime/NMT/VirtualAllocTestType.java failed: '\\[0x[0]*7f7dc4043000 - 0x[0]*7f7dc4083000\\] reserved 256KB for Test' missing from stdout/stderr

Changes: https://git.openjdk.org/jdk/pull/25894/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25894&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8359959
  Stats: 9 lines in 1 file changed: 5 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/25894.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25894/head:pull/25894

PR: https://git.openjdk.org/jdk/pull/25894