RFR: 8321401: Shenandoah: Each mutator must see FullGC before throwing OOM

[Kelvin Nilsen]

Require each thread to observe unproductive Full GC before it throws OOM exception.

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Commit messages:
 - Require each thread to see full GC before throwing OOM

Changes: https://git.openjdk.org/jdk/pull/16985/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16985&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321401
  Stats: 12 lines in 1 file changed: 0 ins; 12 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16985.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16985/head:pull/16985

PR: https://git.openjdk.org/jdk/pull/16985