RFR: 8336707: Contention of ForkJoinPool grows when stealing works [v14]

[Doug Lea]

> This addresses tendencies in previous update to increase fencing, scanning, and signalling that can increase contention, and slow down performance especially on ARM platforms. It also uses more ARM-friendly constructions to reduce overhead (leading to several changes that all of the same form),

Doug Lea 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 32 additional commits since the last revision:

 - Merge branch 'openjdk:master' into JDK-8336707
 - Reduce shutdown overhead and contention
 - dropWaiters now back to releaseAll
 - Merge branch 'openjdk:master' into JDK-8336707
 - reduce shutdown overhead
 - For starvation check #7
 - For starvation checks #6
 - Rervert; recheck
 - For starvation check #5
 - For starvation check #4
 - ... and 22 more: https://git.openjdk.org/jdk/compare/fd15234d...b12be0e1

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21507/files
  - new: https://git.openjdk.org/jdk/pull/21507/files/2efcb442..b12be0e1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21507&range=13
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21507&range=12-13

  Stats: 50321 lines in 1032 files changed: 5717 ins; 41260 del; 3344 mod
  Patch: https://git.openjdk.org/jdk/pull/21507.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21507/head:pull/21507

PR: https://git.openjdk.org/jdk/pull/21507