RFR: 8367450: Shenandoah: Log the composition of the collection set [v2]

[Paul Hohensee]

On Tue, 16 Sep 2025 00:30:37 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> Reuse the same log message from GenShen which details the composition of the live data to be evacuated. In the non-generational modes, all regions are considered young and nothing will be promoted (or old).
>
> William Kemper has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Simplify JFR evac info reporting

Use a copy constructor in shenandoahTrace.cpp, ShenandoahTracer::report_evacuation_info? If you just copy fields, you might miss a few if the definition of ShenandoahEvacuationInformation changes.

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PR Review: https://git.openjdk.org/jdk/pull/27235#pullrequestreview-3230650440