[jdk11u-dev] RFR: 8319456: jdk/jfr/event/gc/collection/TestGCCauseWith[Serial|Parallel].java : GC cause 'GCLocker Initiated GC' not in the valid causes

[Amos Shi]

Backport of [JDK-8311081](https://bugs.openjdk.org/browse/JDK-8311081)

Testing
- Local: Passed, MacOS M1 Laptop
- Pipeline: 
- Testing Machine:

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Commit messages:
 - Backport 7c7f8ea30da7fe552bcd4f2b593fa9aad27dcdb4

Changes: https://git.openjdk.org/jdk11u-dev/pull/2515/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2515&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8319456
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2515.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2515/head:pull/2515

PR: https://git.openjdk.org/jdk11u-dev/pull/2515