RFR: 8365146: Remove LockingMode related code from ppc64 [v3]

[Fredrik Bredberg]

On Wed, 20 Aug 2025 09:05:09 GMT, Fredrik Bredberg <fbredberg at openjdk.org> wrote:

>> Since the integration of [JDK-8359437](https://bugs.openjdk.org/browse/JDK-8359437) the `LockingMode` flag can no longer be set by the user, instead it's declared as `const int LockingMode = LM_LIGHTWEIGHT;`. This means that we can now safely remove all `LockingMode` related code from all platforms.
>> 
>> This PR removes `LockingMode` related code from the **ppc64** platform.
>> 
>> When all the `LockingMode` code has been removed from all platforms, we can go on and remove it from shared (non-platform specific) files as well. And finally remove the `LockingMode` variable itself.
>
> Fredrik Bredberg 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 four additional commits since the last revision:
> 
>  - Merge branch 'master' into 8365146_remove_lockingmode_ppc64
>  - Update after review
>  - Merge branch 'master' into 8365146_remove_lockingmode_ppc64
>  - 8365146: Remove LockingMode related code from ppc64

Thank you for the reviews.

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PR Comment: https://git.openjdk.org/jdk/pull/26697#issuecomment-3209394286