RFR: 8316682: serviceability/jvmti/vthread/SelfSuspendDisablerTest timed out [v3]

[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 three additional commits since the last revision:

 - 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/18944347..4a92986a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24269&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24269&range=01-02

  Stats: 68856 lines in 1040 files changed: 24634 ins; 41255 del; 2967 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