8291650: Add delay to ClassUnloadEventTest before exiting to give time for JVM to send all events before VMDeath

Backport-of: a6564d495b6c2354b82cd49243d3c8793d95f2cb

Author: adinn

test/jdk/com/sun/jdi/ClassUnloadEventTest.java

@@ -102,6 +102,13 @@ private static void runDebuggee() {
         loader = null;
         // Trigger class unloading
         ClassUnloadCommon.triggerUnloading();
+
+        // Short delay to make sure all ClassUnloadEvents have been sent
+        // before VMDeathEvent is genareated.
+        try {
+            Thread.sleep(5000);
+        } catch (InterruptedException e) {
+        }
     }
 
     private static void runDebugger() throws Exception {