RFR: 8378845: Add NoSafepointVerifier to CriticalSection classes

[Thomas Schatzl]

Hi all,

  please review this change that adds `NoSafepointVerifier`s into `GlobalCounter::CriticalSection` and `SingleWriterSynchronizer::CriticalSection` - any safepoint in a critical section of these kinds will deadlock the VM.

This relates to [JDK-8378820](https://bugs.openjdk.org/browse/JDK-8378820) that apparently shows the problem, and originally this change has been written to debug the other. However so far it did not help reproducing it, and it is worth having anyway. 

Testing: gha, tier1-5 run with that change did not show an issue, around 3k runs of the failing test in JDK-8378820 without failures

Thanks,
  Thomas

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Commit messages:
 - * preparations for review
 - * nsv in critical section objects

Changes: https://git.openjdk.org/jdk/pull/29958/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29958&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378845
  Stats: 9 lines in 2 files changed: 6 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/29958.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29958/head:pull/29958

PR: https://git.openjdk.org/jdk/pull/29958