Integrated: 8343649: Shenandoah: ShenandoahEvacInfo event does not follow JFR guidelines

[William Kemper]

Clean backport.

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Commit messages:
 - Backport 2b505eebe5006673f99c58922434f43aab4b7b77

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/135/files
  Webrev: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=135&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343649
  Stats: 127 lines in 9 files changed: 114 ins; 0 del; 13 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/135.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/135/head:pull/135

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/135