RFR: 8318727: Enable parallelism in vmTestbase/vm/gc/concurrent tests

[Aleksey Shipilev]

On Tue, 24 Oct 2023 19:34:52 GMT, Elif Aslan <duke at openjdk.org> wrote:

> The commit includes changes to unblock parallelism for more `hotspot:tier4 tests.` in `test/hotspot/jtreg/vmTestbase/gc/concurrent`  tests.
> 
> Below are the before and after test run comparisons:
> 
> Before:
> 'linux-x86_64-server-release' 9066.56s user 2289.94s system 880% cpu 21:29.15 total
> After:
> linux-x86_64-server-release': 3159.71s user 264.93s system 2891% cpu 1:58.45 total

Marked as reviewed by shade (Reviewer).

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

PR Review: https://git.openjdk.org/jdk/pull/16350#pullrequestreview-1697406435