RFR: 8354115: NMT: VMATree should not accept `uncommit` a `released` region [v3]

[Afshin Zafari]

> At `uncommit` we change the state of the regions to `Reserved`. This is not acceptable to uncommit a  `Released` region and change its state to `Reserved`.
> This case is detected and an invalid `SummaryDiff` (all its contents are -1) is returned. 
> 
> Two test-cases added and run.

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

  a corner case fixed

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/24572/files
  - new: https://git.openjdk.org/jdk/pull/24572/files/7538792c..42a7ce95

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24572&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24572&range=01-02

  Stats: 32 lines in 2 files changed: 21 ins; 1 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/24572.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24572/head:pull/24572

PR: https://git.openjdk.org/jdk/pull/24572