[jdk21u-dev] RFR: 8328647: TestGarbageCollectorMXBean.java fails with C1-only and -Xcomp

[Andrew Lu]

I backport this for parity with 21.0.5-oracle.

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Commit messages:
 - Backport bdd9438b453fedf9b8181ad2615640168638677d

Changes: https://git.openjdk.org/jdk21u-dev/pull/784/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=784&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328647
  Stats: 2 lines in 2 files changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/784.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/784/head:pull/784

PR: https://git.openjdk.org/jdk21u-dev/pull/784