anchor.diff:  
     List<Statement> readStatementList() {
       int length = readUInt();
  -    List<Statement> result = <Statement>[];
  -    result.length = length;
  +    List<Statement> result =
  +        new List<Statement>.filled(length, null, growable: true);
       for (int i = 0; i < length; ++i) {
         result[i] = readStatement();
       }
  
positive.code:       case ConstantTag.ListConstant:
          final DartType typeArgument = readDartType();
          final int length = readUInt();
          final List<Constant> entries = new List<Constant>(length);
          for (int i = 0; i < length; i++) {
            entries[i] = readConstantReference();
          }
  
negative.code: 
    List<NamedExpression> readNamedExpressionList() {
      int length = readUInt();
      List<NamedExpression> result =
          new List<NamedExpression>.filled(length, null, growable: true);
      for (int i = 0; i < length; ++i) {
        result[i] = readNamedExpression();
      }
  