Initializing a final instance is a runtime error

tests/language/constructor_duplicate_final_test.dart

Index: tests/language/constructor_duplicate_final_test.dart
===================================================================
--- tests/language/constructor_duplicate_final_test.dart	(revision 0)
+++ tests/language/constructor_duplicate_final_test.dart	(working copy)
@@ -0,0 +1,24 @@
+// Copyright (c) 2014, 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.
+
+// Check that duplicate initialization of a final field is a runtime error.
+
+
+class Class {
+  final f = 10;
+
+  Class(v) : f = v;  /// 01: runtime error, static type warning
+
+  Class(this.f);  /// 02: runtime error, static type warning
+
+  // If a field is initialized multiple times in the initializer
+  // list, it's a compile time error.
+  Class(this.f) : f = 0;  /// 03: compile-time error
+}
+
+main() {
+  new Class(5);  /// 01: continued
+  new Class(5);  /// 02: continued
+  new Class(5);  /// 03: continued
+}