- Change "static final" to "static const" in the lib/ directory.

lib/compiler/compiler.dart

 // 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.
 
 #library('compiler');
 
 #import('dart:uri');
 #import('implementation/apiimpl.dart');
 
 // Unless explicitly allowed, passing [:null:] for any argument to the
@@ skipping 53 matching lines @@
    * reporting a compilation error. The specification says:
    *
    * "A compile-time error must be reported by a Dart compiler before
    * the erroneous code is executed." and "If a compile-time error
    * occurs within the code of a running isolate A, A is immediately
    * suspended."
    *
    * This means that the compiler can generate code that when executed
    * terminates execution.
    */
-  static final Diagnostic ERROR = const Diagnostic(1, 'error');
+  static const Diagnostic ERROR = const Diagnostic(1, 'error');
 
   /**
    * A warning as identified by the "Dart Programming Language
    * Specification" [http://www.dartlang.org/docs/spec/].
    */
-  static final Diagnostic WARNING = const Diagnostic(2, 'warning');
+  static const Diagnostic WARNING = const Diagnostic(2, 'warning');
 
   /**
    * Any other warning that is not covered by [WARNING].
    */
-  static final Diagnostic LINT = const Diagnostic(4, 'lint');
+  static const Diagnostic LINT = const Diagnostic(4, 'lint');
 
   /**
    * Informational messages.
    */
-  static final Diagnostic INFO = const Diagnostic(8, 'info');
+  static const Diagnostic INFO = const Diagnostic(8, 'info');
 
   /**
    * Informational messages that shouldn't be printed unless
    * explicitly requested by the user of a compiler.
    */
-  static final Diagnostic VERBOSE_INFO = const Diagnostic(16, 'verbose info');
+  static const Diagnostic VERBOSE_INFO = const Diagnostic(16, 'verbose info');
 
   /**
    * An internal error in the compiler.
    */
-  static final Diagnostic CRASH = const Diagnostic(32, 'crash');
+  static const Diagnostic CRASH = const Diagnostic(32, 'crash');
 
   /**
    * An [int] representation of this kind. The ordinals are designed
    * to be used as bitsets.
    */
   final int ordinal;
 
   /**
    * The name of this kind.
    */
   final String name;
 
   /**
    * This constructor is not private to support user-defined
    * diagnostic kinds.
    */
   const Diagnostic(this.ordinal, this.name);
 
   String toString() => name;
 }