Fix for issue 1835: record the 'final' information in the DeclaredIdentifier.

tests/language/src/FinalForInVariableTest.dart

Index: tests/language/src/FinalForInVariableTest.dart
===================================================================
--- tests/language/src/FinalForInVariableTest.dart	(revision 0)
+++ tests/language/src/FinalForInVariableTest.dart	(revision 0)
@@ -0,0 +1,9 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+main() {
+  for (final i in [1, 2, 3]) {
+    i = 4; /// 01: compile-time error
+  }
+}