RFR: 8318605: Enable parallelism in vmTestbase/nsk/stress/stack tests

[Elif Aslan]

The commit includes changes to unblock parallelism vmTestbase/nsk/stress/stack tests.
GHA tested.
Command below succeeded 
`make test TEST=vmTestbase/nsk/stress/stack JTREG=REPEAT_COUNT=100`

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Commit messages:
 - Enable parallelism in vmTestbase/nsk/stress/stack tests

Changes: https://git.openjdk.org/jdk/pull/18037/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18037&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318605
  Stats: 24 lines in 1 file changed: 0 ins; 24 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/18037.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18037/head:pull/18037

PR: https://git.openjdk.org/jdk/pull/18037