[jdk17u-dev] RFR: 8321815: Shenandoah: gc state should be synchronized to java threads only once per safepoint

[William Kemper]

Resolved conflict with unused method

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

Commit messages:
 - Backport 808a03927c153581cbece93a4f5a4f8242b61ef5

Changes: https://git.openjdk.org/jdk17u-dev/pull/2177/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2177&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321815
  Stats: 45 lines in 5 files changed: 31 ins; 5 del; 9 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2177.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2177/head:pull/2177

PR: https://git.openjdk.org/jdk17u-dev/pull/2177