[jdk17u-dev] RFR: 8316410: GC: Make TestCompressedClassFlags use createTestJvm

[Goetz Lindenmaier]

I backport this to improve testing in17.

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

Commit messages:
 - Backport e649c563242a876a20007470c9412311ffa2a568

Changes: https://git.openjdk.org/jdk17u-dev/pull/2946/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2946&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316410
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2946.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2946/head:pull/2946

PR: https://git.openjdk.org/jdk17u-dev/pull/2946