RFR: 8038332: The trace event vm/class/load is not always being sent

[Max Ockner]

Hello,

Please review this small fix which causes the vm/class/load event to be 
fired from JVM_DefineClass() and JVM_DefineClassWithSource().

Webrev: http://cr.openjdk.java.net/~mockner/8038332/
Bug: https://bugs.openjdk.java.net/browse/JDK-8038332

The vm/class/load event  (EventClassLoad) was previously fired in 2 places:

SystemDictionary::parse_stream
SystemDictionary::resolve_instance_class_or_null

parse_stream is the standard option for creating a klass from a stream, 
but JVM_DefineClass uses a different function:

SystemDictionary::resolve_from_stream.

This did not fire a vm/class/load event. Now it does fire the event.

Sanity tested with jtreg runtime. Issue was reproduced and tested using 
the reproducer script attached to the bug

Thanks,
Max