RFR: 8351187: Add JFR monitor notification event [v3]

[Leonid Mesnik]

On Wed, 5 Mar 2025 12:55:46 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> We have `JavaMonitorWait` event, but no symmetric `JavaMonitorNotify` event. Notifications are important/interesting to track as well, for example to correlate the delay between notification and eventual wake up.
>> 
>> Providing this event would also replace one of of the RT counters that are going away in [JDK-8348829](https://bugs.openjdk.org/browse/JDK-8348829).
>> 
>> This counter is disabled by default to keep any potential impact low. We can consider flipping it to enabled by default later.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 server fastdebug, `jdk_jfr`
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rewrite test to RecordingStream

Test changes looks good.

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Marked as reviewed by lmesnik (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23901#pullrequestreview-2662297970