[jdk21u] RFR: 8318607: Enable parallelism in vmTestbase/nsk/stress/jni tests

[Elif Aslan]

Clean backport to enable parallelism in vmTestbase/nsk/stress/jni tests

Tested with GHA

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Commit messages:
 - Backport 43f31d73852d63ccdcc2dcd8d6c7355435a50fb3

Changes: https://git.openjdk.org/jdk21u/pull/429/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=429&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318607
  Stats: 24 lines in 1 file changed: 0 ins; 24 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u/pull/429.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/429/head:pull/429

PR: https://git.openjdk.org/jdk21u/pull/429