Change StackOverflowException to be an Error.

lib/core/exceptions.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.
 
 // Exceptions are thrown either by the VM or from Dart code.
 
 /**
  * Interface implemented by all core library exceptions.
  * Defaults to an implementation that only carries a simple message.
  */
@@ skipping 37 matching lines @@
   String toString() => "Closure argument mismatch";
 }
 
 
 class ObjectNotClosureException implements Exception {
   const ObjectNotClosureException();
   String toString() => "Object is not closure";
 }
 
 
-class StackOverflowException implements Exception {
-  const StackOverflowException();
-  String toString() => "Stack Overflow";
-}
-
-
 /**
  * Exception thrown when a string or some other data does not have an expected
  * format and cannot be parsed or processed.
  */
 class FormatException implements Exception {
   /**
    * A message describing the format error.
    */
   final String message;
 
@@ skipping 73 matching lines @@
 }
 
 /**
  * Exception thrown when a runtime error occurs.
  */
 class RuntimeError implements Exception {
   final message;
   RuntimeError(this.message);
   String toString() => "RuntimeError: $message";
 }