anchor.diff:  
     @override
     Map<Abi, int?> get size => throw reason;
  +
  +  @override
  +  int? getSizeFor(Abi abi) => throw reason;
   }
   
   class PrimitiveNativeTypeCfe implements NativeTypeCfe {
  
positive.code:       elementType.size.map((abi, size) => MapEntry(abi, size * length));
  
    @override
    Map<Abi, int?> get alignment => elementType.alignment;
  
    // Note that we flatten multi dimensional arrays.
    @override
  
negative.code:     int? unionSize = 1;
      int? unionAlignment = 1;
      for (int i = 0; i < types.length; i++) {
        final int? size = types[i].getSizeFor(abi);
        int? alignment = types[i].getAlignmentFor(abi);
        unionSize = max(unionSize, size);
        unionAlignment = max(unionAlignment, alignment);
      }
  