RFR: 8354115: NMT: VMATree should not accept `uncommit` a `released` region [v2]

[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:

  returns invalid SummaryDiff, instead of assert.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24572/files
  - new: https://git.openjdk.org/jdk/pull/24572/files/4c10038c..7538792c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24572&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24572&range=00-01

  Stats: 23 lines in 3 files changed: 14 ins; 0 del; 9 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