[jdk23] RFR: 8334594: Generational ZGC: Deadlock after OopMap rewrites in 8331572

[Aleksey Shipilev]

Clean backport to fix a deadlock.

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Commit messages:
 - Backport 05ff3185edd25b381a97f6879f496e97b62dddc2

Changes: https://git.openjdk.org/jdk/pull/19851/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19851&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334594
  Stats: 12 lines in 6 files changed: 3 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/19851.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19851/head:pull/19851

PR: https://git.openjdk.org/jdk/pull/19851