RFR: 8369913: Parallel: Refactor PSAdjustTask [v2]

[Joel Sikström]

On Fri, 31 Oct 2025 12:46:47 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

>> Cleanup roots processing (adjusting/remapping) during the adjust-phase of full-gc, so that relevant roots are grouped together with some documentations. Also, the use of `SubTasksDone` is replaced with a `volatile bool`, which is more transparent in the context.
>> 
>> Test: tier1-5
>
> Albert Mingkun Yang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - review
>  - Merge branch 'master' into pgc-adjust-root
>  - pgc-adjust-root

Marked as reviewed by jsikstro (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/27822#pullrequestreview-3404576736