[jdk21u] RFR: 8318757: VM_ThreadDump asserts in interleaved ObjectMonitor::deflate_monitor calls

Mon Nov 20 12:34:01 UTC 2023

Fixes an important race condition in monitor deflation code. Applies cleanly.

Additional testing:
 - [ ] Linux AArch64 fastdebug `tier1 tier2 tier3 tier4`

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Commit messages:
 - Backport 87be6b69fe985eee01fc3344f9153d774db792c1

Changes: https://git.openjdk.org/jdk21u/pull/384/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=384&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318757
  Stats: 426 lines in 11 files changed: 208 ins; 147 del; 71 mod
  Patch: https://git.openjdk.org/jdk21u/pull/384.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/384/head:pull/384

PR: https://git.openjdk.org/jdk21u/pull/384