[jdk17u-dev] RFR: 8287227: Shenandoah: A couple of virtual thread tests failed with iu mode even without Loom enabled.

[William Kemper]

This clean backport depends on https://github.com/openjdk/jdk17u-dev/pull/1448

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Commit messages:
 - Backport 210a06a287521a554316a9052bd9fdf616c7b884
 - Merge branch 'jdk17u-master' into jdk17u-dev-8277654
 - Backport 3d39f09c6cdc875b44147b4e84e496b6abf93996

Changes: https://git.openjdk.org/jdk17u-dev/pull/1479/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1479&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8287227
  Stats: 140 lines in 2 files changed: 9 ins; 125 del; 6 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1479.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1479/head:pull/1479

PR: https://git.openjdk.org/jdk17u-dev/pull/1479