Only remove current node from wait queue.

ir/ir/irgopt.c

@@ -127,10 +127,10 @@ void local_optimize_graph(ir_graph *irg)
  */
 static void opt_walker(ir_node *n, void *env)
 {
-	pdeq    *waitq     = (pdeq *)env;
-	ir_node *optimized = optimize_in_place_2(n);
-	set_irn_link(optimized, NULL);
+	pdeq *waitq = (pdeq *)env;
+	set_irn_link(n, NULL);
 
+	ir_node *optimized = optimize_in_place_2(n);
 	if (optimized != n) {
 		enqueue_users(n, waitq);
 		exchange(n, optimized);