RFR: 8319326: GC: Make TestParallelRefProc use createTestJavaProcessBuilder [v3]

[Ramkumar Sunderbabu]

> Summary of change:
> executeLimitedTestJava changed to executeTestJava to allow flags to be propagated to forked processes.
> `@requires vm.gc == null` - this line is added to skip runs that use GC flags in test vm options. Allowing GC flags will result in VM initialization error ("Multiple garbage collectors selected").
> 
> Testing:
> HS Tiers 1 and 2 
> Ran with all flag combinations in CI

Ramkumar Sunderbabu has updated the pull request incrementally with one additional commit since the last revision:

  test split into sections

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/28508/files
  - new: https://git.openjdk.org/jdk/pull/28508/files/a3edb127..3d1f3226

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28508&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28508&range=01-02

  Stats: 60 lines in 1 file changed: 33 ins; 5 del; 22 mod
  Patch: https://git.openjdk.org/jdk/pull/28508.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28508/head:pull/28508

PR: https://git.openjdk.org/jdk/pull/28508