[parser] better error message for generator constructors

test/message/class-constructor-accessor.out

Index: test/message/class-constructor-accessor.out
diff --git a/test/message/class-constructor-accessor.out b/test/message/class-constructor-accessor.out
new file mode 100644
index 0000000000000000000000000000000000000000..8776f54db16a1fc4169665ff924c0aac454a24d7
--- /dev/null
+++ b/test/message/class-constructor-accessor.out
@@ -0,0 +1,7 @@
+# Copyright 2014 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: Class constructor may not be an accessor
+  get constructor() {}
+      ^^^^^^^^^^^
+SyntaxError: Class constructor may not be an accessor