[jdk21u-dev] RFR: 8309757: com/sun/jdi/ReferrersTest.java fails with virtual test thread factory

[Goetz Lindenmaier]

I backport this for parity with 21.0.4-oracle.

Resolved ProblemList, will mark clean.

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Commit messages:
 - Backport d7251c1755779f8c4fdeac16ccb797ed45b1dfd4

Changes: https://git.openjdk.org/jdk21u-dev/pull/367/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=367&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8309757
  Stats: 5 lines in 2 files changed: 3 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/367.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/367/head:pull/367

PR: https://git.openjdk.org/jdk21u-dev/pull/367