Change NotImplementedException to UnimplementedError.

runtime/lib/function_patch.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.
 
 patch class Function {
   /* patch */ static apply(Function function,
                            List positionalArguments,
                            [Map<String,Dynamic> namedArguments]) {
-    throw new NotImplementedException('Function.apply not implemented');
+    throw new UnimplementedError('Function.apply not implemented');
   }
 }