Change new List(n) to return fixed length list.

sdk/lib/utf/utf32.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.
 
 part of dart.utf;
 
 /**
  * Decodes the UTF-32 bytes as an iterable. Thus, the consumer can only convert
  * as much of the input as needed. Determines the byte order from the BOM,
  * or uses big-endian as a default. This method always strips a leading BOM.
@@ skipping 204 matching lines @@
     } else if (hasUtf32leBom(utf32EncodedBytes, offset, length)) {
       return new Utf32leBytesDecoder(utf32EncodedBytes, offset + 4, length - 4,
           false, replacementCodepoint);
     } else {
       return new Utf32beBytesDecoder(utf32EncodedBytes, offset, length, false,
           replacementCodepoint);
     }
   }
 
   List<int> decodeRest() {
-    List<int> codeunits = new List<int>.fixedLength(remaining);
+    List<int> codeunits = new List<int>(remaining);
     int i = 0;
     while (moveNext()) {
       codeunits[i++] = current;
     }
     return codeunits;
   }
 
   int get current => _current;
 
   bool moveNext() {
@@ skipping 93 matching lines @@
     value += (utf32EncodedBytesIterator.current << 24);
     return value;
   }
 }
 
 bool _validCodepoint(int codepoint) {
   return (codepoint >= 0 && codepoint < UNICODE_UTF16_RESERVED_LO) ||
       (codepoint > UNICODE_UTF16_RESERVED_HI &&
       codepoint < UNICODE_VALID_RANGE_MAX);
 }