RFR: 8257967: JFR: Events for loaded agents [v4]

[Andrew Dinn]

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On Wed, 8 Mar 2023 23:28:52 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

>> Markus Grönlund has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - remove JVMPI
>>  - cleanup
>
> No need to load any JFR classes. No change to startup logic.

@mgronlun Why mark Java agents as command-line or dynamic using `initializationMethod = "premain"/"agentMain"` and mark native agents using `dynamic = true/false`? Why not use `dynamic` for both?

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PR: https://git.openjdk.org/jdk/pull/12923