RFR: 8369038: Use NMethodMarkingScope and ThreadsClaimTokenScope in psParallelCompact

[duke]

On Thu, 2 Oct 2025 12:23:32 GMT, Francesco Andreuzzi <fandreuzzi at openjdk.org> wrote:

> Replace `StrongRootsScope` with `ThreadsClaimTokenScope` in `MarkFromRootsTask ` to be more precise with what is needed and why.
> 
> - `MarkFromRootsTask` uses `MarkingNMethodClosure` (in `PCAddThreadRootsMarkingTaskClosure`), so we also need `NMethodMarkingScope`.
> - `active_workers ` is guaranteed to be `> 0`
> 
> Passes tier1 and tier2 (fastdebug).

@fandreuz 
Your change (at version 1ab02decd10923287786ec8ce018db4b45ab0f3e) is now ready to be sponsored by a Committer.

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PR Comment: https://git.openjdk.org/jdk/pull/27607#issuecomment-3365222423