RFR: 8335347: GenShen: Revert change that has adaptive heuristic ignore abbreviated cycles

[William Kemper]

Trivial conflict with not-yet-backported improvements to OOM handling.

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Commit messages:
 - Remove part of upstream change picked up in cherry-pick
 - Backport 7542e909d1b4fb8a9a29ab5caf61a6be792f0f03

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/67/files
  Webrev: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=67&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8335347
  Stats: 26 lines in 10 files changed: 1 ins; 14 del; 11 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/67.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/67/head:pull/67

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/67