Fix mac/git renaming case failure. Aaarrrrgggghhhh.

utils/string_encoding/utf8_impl.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.
 
 final int _UTF8_ONE_BYTE_MAX = 0x7f;
 final int _UTF8_TWO_BYTE_MAX = 0x7ff;
 final int _UTF8_THREE_BYTE_MAX = 0xffff;
 
 final int _UTF8_LO_SIX_BIT_MASK = 0x3f;
 
@@ skipping 201 matching lines @@
       codepointBufferLength++;
   });
 
   List<int> codepointBuffer = new List<int>(codepointBufferLength);
   int i = 0;
   apply(void _(int value) {
       codepointBuffer[i++] = value;
   });
   return codepointBuffer;
 }