RFR: Merge jdk18

[Jesper Wilhelmsson]

Forwardport JDK 18 -> JDK 19

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Commit messages:
 - Merge
 - 8278574: update --help-extra message to include default value of --finalization option
 - 8278389: SuspendibleThreadSet::_suspend_all should be volatile/atomic
 - 8278575: update jcmd GC.finalizer_info to list finalization status

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - master: https://webrevs.openjdk.java.net/?repo=jdk&pr=6873&range=00.0
 - jdk18: https://webrevs.openjdk.java.net/?repo=jdk&pr=6873&range=00.1

Changes: https://git.openjdk.java.net/jdk/pull/6873/files
  Stats: 29 lines in 4 files changed: 12 ins; 1 del; 16 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6873.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6873/head:pull/6873

PR: https://git.openjdk.java.net/jdk/pull/6873