RFR: 8256302: releasing oopStorage when deflating allows for faster deleting [v5]

[Daniel D. Daugherty]

> Releasing ObjectMonitor oopStorage earlier when deflating allows ObjectMonitor
> deletion by a JavaThread (usually the MonitorDeflationThread) to happen while a
> ThreadBlockInVM helper is in place. This should improve time-to-safepoint.

Daniel D. Daugherty 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 tag 'jdk-21+25' into JDK-8256302
   
   Added tag jdk-21+25 for changeset a46b5acc
 - Allow ObjectMonitor::_object to be reset to nullptr when it is released which allows the code to be cleaner.
 - Merge tag 'jdk-21+23' into JDK-8256302
   
   Added tag jdk-21+23 for changeset 6d4782bc
 - address the easy dholmes and kimbarrett CR comments
 - 8256302: releasing oopStorage when deflating allows for faster deleting

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11296/files
  - new: https://git.openjdk.org/jdk/pull/11296/files/958c5e95..51310bed

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11296&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11296&range=03-04

  Stats: 59495 lines in 1425 files changed: 40595 ins; 10373 del; 8527 mod
  Patch: https://git.openjdk.org/jdk/pull/11296.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/11296/head:pull/11296

PR: https://git.openjdk.org/jdk/pull/11296