RFR: 8301341: LinkedTransferQueue does not respect timeout for poll() [v4]

[Doug Lea]

> This now uses Thread.isVirtual to distinguish spin vs immediate block cases, enabling re-introduction of spin control from the previous version, removing anomalies like this one.

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 four additional commits since the last revision:

 - Merge branch 'openjdk:master' into JDK-8301341
 - Overhaul LTQ and SQ to use common blocking and matching mechanics
 - Merge branch 'openjdk:master' into JDK-8301341
 - Use Thread.isVirtual to distinguish spin vs immediate block cases

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14317/files
  - new: https://git.openjdk.org/jdk/pull/14317/files/67a145a0..71b9c8bf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14317&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14317&range=02-03

  Stats: 565 lines in 23 files changed: 471 ins; 57 del; 37 mod
  Patch: https://git.openjdk.org/jdk/pull/14317.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14317/head:pull/14317

PR: https://git.openjdk.org/jdk/pull/14317