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

[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.

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Commit messages:
 - Use Thread.isVirtual to distinguish spin vs immediate block cases

Changes: https://git.openjdk.org/jdk/pull/14317/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14317&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301341
  Stats: 131 lines in 1 file changed: 73 ins; 28 del; 30 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