RFR: 8257967: JFR: Events for loaded agents [v10]

[Markus Grönlund]

On Tue, 14 Mar 2023 12:22:16 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

>> n.b. that also applies for accesses/updates to field _next.
>
> I wanted all accesses to use the iterator. The only access is given to the iterator and AgentList by way of being friends. No need to expose more.

I updated all external access to use getters/setters.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/12923#discussion_r1153703241