[jdk17u-dev] RFR: 8324755: Enable parallelism in vmTestbase/gc/gctests/LargeObjects tests

[Soumadipta Roy]

Backporting the fix for https://bugs.openjdk.org/browse/JDK-8324755 merged as part of openjdk/jdk#18798.
https://github.com/openjdk/jdk/commit/003e86fe38ca1b809418f6282336e259862d0776.patch could be applied cleanly.

Run details on AL2_x86_64:

Fastdebug
before: 2114.20s user 722.07s system 394% cpu 11:58.39 total
after: 2220.88s user 484.73s system 1530% cpu 2:56.73 total

Release
before: 1892.74s user 611.37s system 378% cpu 11:01.70 total
after: 1747.61s user 559.69s system 1568% cpu 2:27.14 total

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Commit messages:
 - Backport 003e86fe38ca1b809418f6282336e259862d0776

Changes: https://git.openjdk.org/jdk17u-dev/pull/2561/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2561&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324755
  Stats: 115 lines in 5 files changed: 0 ins; 115 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2561.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2561/head:pull/2561

PR: https://git.openjdk.org/jdk17u-dev/pull/2561