RFR: 8336707: Contention of ForkJoinPool grows when stealing works [v12]

[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 29 additional commits since the last revision:

 - 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
 - For starvation check #3
 - For starvation check #2
 - For starvation check
 - ... and 19 more: https://git.openjdk.org/jdk/compare/715d4d24...b211c2ab

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21507/files
  - new: https://git.openjdk.org/jdk/pull/21507/files/97d920aa..b211c2ab

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21507&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21507&range=10-11

  Stats: 122009 lines in 443 files changed: 16740 ins; 102969 del; 2300 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