RFR: 8365939: [Redo] G1: Move collection set related full gc reset code into abandon_collection_set() method

[Ivan Walulya]

On Tue, 26 Aug 2025 17:44:04 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   please review this attempt on clearing the young regions cset group early in `abandon_collection_set()` during full gc.
> 
> The initial attempt failed because some verification code depended on the young gen remembered set being `Complete` and contain valid card entries.
> 
> This change fixes both:
> 
> - we need to clear the `young_regions_cset_group` with `uninstall_group_cardsets` being `true` to a) remove the cards and b) make it incomplete
> - some verification expects that the young gen remset is always complete, which is not necessary during full gc.
> 
> Test: tier1-5, the failing test that caused the failures in JDK-8365780 passes always.
> 
> Thanks,
>   Thomas

Marked as reviewed by iwalulya (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/26948#pullrequestreview-3160877381