Beautify syntax error for unterminated argument list

test/message/unterminated-arg-list.out

Index: test/message/unterminated-arg-list.out
diff --git a/test/message/export-duplicate.out b/test/message/unterminated-arg-list.out
similarity index 57%
copy from test/message/export-duplicate.out
copy to test/message/unterminated-arg-list.out
index e88779f5805370e47565c87126674e4b934d7c19..5be2b3d90c28dffc0382a5463219719ecd7cb887 100644
--- a/test/message/export-duplicate.out
+++ b/test/message/unterminated-arg-list.out
@@ -1,7 +1,8 @@
 # Copyright 2015 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-*%(basename)s:9: SyntaxError: Duplicate export of 'a'
-export { a, b };
-         ^
-SyntaxError: Duplicate export of 'a'
+
+*%(basename)s:7: SyntaxError: missing ) after argument list
+}
+^
+SyntaxError: missing ) after argument list