jdi tests: log ClassPrepareEvent referenceType

ClassPrepareEvent for org.eclipse.debug.jdi.tests.program.MainClass
missing after 10000ms

org.eclipse.jdt.debug.jdi.tests/tests/org/eclipse/debug/jdi/tests/ClassPrepareEventWaiter.java

@@ -35,6 +35,7 @@ public ClassPrepareEventWaiter(EventRequest request, boolean shouldGo, String cl
 	 */
 	@Override
 	public boolean classPrepare(ClassPrepareEvent event) {
+		System.out.println("classPrepare:" + event + " " + event.referenceType().name());
 		if (event.referenceType().name().equals(fClassName)) {
 			notifyEvent(event);
 			return fShouldGo;

org.eclipse.jdt.debug.jdi.tests/tests/org/eclipse/debug/jdi/tests/EventReader.java

@@ -63,7 +63,6 @@ public synchronized void addEventListener(EventListener listener) {
 	 * Returns whether the VM should be resumed.
 	 */
 	private boolean dispath(Event event, EventListener listener) {
-		System.out.println(event);
 		if (event instanceof AccessWatchpointEvent) {
 			return listener.accessWatchpoint((AccessWatchpointEvent) event);
 		}

org.eclipse.jdt.debug/jdi/org/eclipse/jdi/internal/event/ClassPrepareEventImpl.java

@@ -77,4 +77,10 @@ public ReferenceType referenceType() {
 	public String classSignature() {
 		return referenceType().signature();
 	}
+
+	@Override
+	public String toString() {
+		return super.toString() + " referenceType=" + referenceType().name(); //$NON-NLS-1$
+	}
+
 }