[jdk17u-dev] RFR: 8300053: Shenandoah: Handle more GCCauses in ShenandoahControlThread::request_gc

[Aleksey Shipilev]

Clean backport to catch a corner case for Shenandoah.

Additional testing:
 - [x] macos-aarch64-server-fastdebug build
 - [ ] GHA

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Commit messages:
 - Backport cac72a60181d3570562f8534c691528d06e40cb8

Changes: https://git.openjdk.org/jdk17u-dev/pull/1409/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1409&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300053
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1409.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1409/head:pull/1409

PR: https://git.openjdk.org/jdk17u-dev/pull/1409