RFR: 8336914: Shenandoah: Missing verification steps after JDK-8255765

[William Kemper]

Almost clean.

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Commit messages:
 - Backport e51e40c2b9f51d012c01407e0b8dadaab464753e

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/127/files
  Webrev: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=127&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336914
  Stats: 3 lines in 1 file changed: 2 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/127.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/127/head:pull/127

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/127