[jdk11u-dev] RFR: 8273433: Enable parallelism in vmTestbase_nsk_sysdict tests

[Aleksey Shipilev]

Clean backport to improve testing.

Additional testing:
 - [x] Linux x86_64 fastdebug `vmTestbase_nsk_sysdict` passes

-------------

Commit messages:
 - Backport 5ca26cbddbdd47a73cc141a6215dc89c53841d4a

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/778/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=778&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273433
  Stats: 20 lines in 20 files changed: 0 ins; 20 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/778.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/778/head:pull/778

PR: https://git.openjdk.java.net/jdk11u-dev/pull/778