[jdk22u] RFR: 8320707: Virtual thread test updates

Mon Apr 22 13:42:54 UTC 2024

Test-only backport that simplifies Loom maintenance. This would make subsequent backports clean.

Additional testing:
 - [ ] MacOS AArch64 server fastdebug, `jdk_loom hotspot_loom`

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Commit messages:
 - Backport b67b71cd87c62f15d5b73f923c300d0f77c988f5

Changes: https://git.openjdk.org/jdk22u/pull/160/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk22u&pr=160&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320707
  Stats: 981 lines in 16 files changed: 618 ins; 213 del; 150 mod
  Patch: https://git.openjdk.org/jdk22u/pull/160.diff
  Fetch: git fetch https://git.openjdk.org/jdk22u.git pull/160/head:pull/160

PR: https://git.openjdk.org/jdk22u/pull/160