RFR: 8316682: serviceability/jvmti/vthread/SelfSuspendDisablerTest timed out [v5]

[Serguei Spitsyn]

> This fixes the issue with lack of synchronization between JVMTI thread suspend and resume functions in a self-suspend case. More detailed fix description is in the first PR comment.
> 
> Testing: Ran mach5 tiers 1-6.

Serguei Spitsyn has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:

 - “Merge”
 - review: added general comment about sync between suspend_thread and resume_thread
 - Merge
 - some cleanup
 - 8316682: serviceability/jvmti/vthread/SelfSuspendDisablerTest timed out

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24269/files
  - new: https://git.openjdk.org/jdk/pull/24269/files/df99ba15..f2c4a136

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24269&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24269&range=03-04

  Stats: 289018 lines in 2561 files changed: 84046 ins; 194950 del; 10022 mod
  Patch: https://git.openjdk.org/jdk/pull/24269.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24269/head:pull/24269

PR: https://git.openjdk.org/jdk/pull/24269