6618401: Input method cannot be selected from System menu

Summary: lock.wait() added in sun.awt.im.InputMethodManager.showInputMethodMenuOnRequesterEDT()
Reviewed-by: alexp

src/share/classes/sun/awt/im/InputMethodManager.java

@@ -358,6 +358,7 @@ class ExecutableInputMethodManager extends InputMethodManager
         AppContext requesterAppContext = SunToolkit.targetToAppContext(requester);
         synchronized (lock) {
             SunToolkit.postEvent(requesterAppContext, event);
+            lock.wait();
         }
 
         Throwable eventThrowable = event.getThrowable();