RFR: 8342818: Implement JEP 509: JFR CPU-Time Profiling [v50]

[Johannes Bechberger]

On Wed, 4 Jun 2025 15:07:32 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix build
>
> src/hotspot/share/jfr/support/jfrThreadLocal.cpp line 586:
> 
>> 584: }
>> 585: 
>> 586: bool JfrThreadLocal::try_acquire_cpu_time_jfr_dequeue_lock() {
> 
> ...and this one is not `try_`, but the actual "blocking" acquire.

But it fails if the lock state is already on `DEQUEUE`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25302#discussion_r2126907622