Avoid UTF-8 decoding in num.toString.

runtime/lib/num.dart

Index: runtime/lib/num.dart
===================================================================
--- runtime/lib/num.dart	(revision 0)
+++ runtime/lib/num.dart	(revision 0)
@@ -0,0 +1,7 @@
+// 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.
+
+class _Num extends num {

[Ivan Posva, 2014/08/19 20:37:18]

We should not extend num, if anything at all this should implement num. In any
case this should really be an abstract class. You can also roll the code from
the patch into here, as this is not a SDK class and is internal to the VM.

[koda, 2014/08/19 21:15:18]

Done.

+
+}