HHH-6102 - ISE should be thrown when EM is colsed and joinTransaction is called, even with RESOURCE-LOCAL TX

hibernate-entitymanager/src/main/java/org/hibernate/ejb/AbstractEntityManagerImpl.java

@@ -1143,6 +1143,9 @@ public abstract class AbstractEntityManagerImpl implements HibernateEntityManage
 	}
 
 	public void joinTransaction() {
+		if( !isOpen() ){
+			throw new IllegalStateException( "EntityManager is closed" );
+		}
 		joinTransaction( false );
 	}