RFR: 8337511: Implement JEP 404: Generational Shenandoah (Experimental) [v12]

[Aleksey Shipilev]

On Fri, 29 Nov 2024 16:00:52 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> This PR merges JEP 404, a generational mode for the Shenandoah garbage collector. The JEP can be viewed here: https://openjdk.org/jeps/404. We would like to target JDK24 with this PR.
>
> William Kemper has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 533 commits:
> 
>  - Merge remote-tracking branch 'jdk/master' into great-genshen-pr-redux
>  - Problem list Shenandoah TestAllocOutOfMemory on ppc64
>  - Merge remote-tracking branch 'shenandoah/master' into great-genshen-pr-redux
>  - 8344985: GenShen: Refactor arraycopy barrier for generational mode
>    
>    Reviewed-by: shade
>  - Remove incomplete test case
>  - Merge remote-tracking branch 'shenandoah/master' into great-genshen-pr-redux
>  - Merge
>  - 8344779: GenShen: Consolidate shared heap region closures into one header
>    
>    Reviewed-by: kdnilsen, ysr
>  - 8344797: GenShen: Update and rename confusing method
>    
>    Reviewed-by: ysr, kdnilsen
>  - Merge remote-tracking branch 'shenandoah/master' into great-genshen-pr-redux
>  - ... and 523 more: https://git.openjdk.org/jdk/compare/a80ccf2c...f29d741c

Marked as reviewed by shade (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/21273#pullrequestreview-2470311607