RFR: 8334147: Shenandoah: Avoid taking lock for disabled free set logging [v3]

[William Kemper]

> Not clean. Backport to only take lock for logging when log level is enabled.

William Kemper has updated the pull request incrementally with one additional commit since the last revision:

  Fix old gen usage of shFreeSet::log_status

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Changes:
  - all: https://git.openjdk.org/shenandoah-jdk21u/pull/113/files
  - new: https://git.openjdk.org/shenandoah-jdk21u/pull/113/files/d4ee79ea..275e76d9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=113&range=02
 - incr: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=113&range=01-02

  Stats: 4 lines in 1 file changed: 0 ins; 3 del; 1 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/113.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/113/head:pull/113

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/113