check for iro in is_NODE functions (saves a Load)

ir/be/scripts/generate_new_opcodes.pl

@@ -88,7 +88,7 @@ foreach my $op (keys(%nodes)) {
 
 	push(@obst_opvar, "ir_op *op_$op = NULL;\n");
 	push(@obst_get_opvar, "ir_op *get_op_$op(void)         { return op_$op; }\n");
-	push(@obst_get_opvar, "int    is_$op(const ir_node *n) { return get_irn_op(n) == op_$op; }\n\n");
+	push(@obst_get_opvar, "int    is_$op(const ir_node *n) { return get_irn_opcode(n) == iro_$op; }\n\n");
 
 	push(@obst_is_archirn, "is_$op(node)");