Move frog/leg to lib/compiler/implementation.

frog/leg/lib/mock.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.
-
-// Mocks of things that Leg cannot read directly.
-
-// TODO(ahe): Remove this file.
-
-class AssertionError {}
-class TypeError extends AssertionError {}
-
-class FallThroughError {
-  const FallThroughError();
-  String toString() => "Switch case fall-through.";
-}
-
-// TODO(ahe): VM specfic exception?
-class InternalError {
-  const InternalError(this._msg);
-  String toString() => "InternalError: '${_msg}'";
-  final String _msg;
-}
-
-// TODO(ahe): VM specfic exception?
-class StaticResolutionException implements Exception {}
-
-void assert(condition) {}
-
-// TODO(ahe): Not sure ByteArray belongs in the core library.
-interface ByteArray extends List default _InternalByteArray {
-  ByteArray(int length);
-}
-
-class _InternalByteArray {
-  factory _InternalByteArray(int length) {
-    throw new UnsupportedOperationException("new ByteArray($length)");
-  }
-}
-
-// TODO(ahe): This definitely does not belong in the core library.
-void exit(int exitCode) {
-  throw new UnsupportedOperationException("exit($exitCode)");
-}