Update JFR mirror event registration to account for new JDK class

[roberttoyonaga]

This change (openjdk/jdk#16411) in OpenJDK will cause com.oracle.svm.hosted.jfr.JfrEventSubstitution#createMirrorEventsMapping to fail. Specifically, the introduction of MirrorEvents.java will require us to modify how we register JFR mirror events in SubstrateVM.

I can help do this maintenance once labsJDK is up to date with the OpenJDK changes that will cause this problem.

[zapster]

Thanks @roberttoyonaga! We are already working on integrating JDK 22+22. I've pushed the current state to #7748, but note that it is work in progress and the labsjdk builds are not yet public.

Regarding the mirror events change, for now we have only removed references to the legacy code, but you are right, we need to adopt MirrorEvents.java as well. We are still tackling other breaking JDK changes, but I hope that it wont take to long.

In any case, comments/suggestion/contributions to the WIP very much appreciated.

[roberttoyonaga]

Hi @zapster! Thank you. I've added a comment on the WIP internal PR mirror that explains in more detail what I mean.