anchor.diff:  
   @pragma("vm:entry-point")
   class _Float64ArrayView extends _TypedListView
  -    with _DoubleListMixin<Float64List>
  +    with _DoubleListMixin, _TypedDoubleListMixin<Float64List>
       implements Float64List {
     // Constructor.
     @pragma("vm:exact-result-type", _Float64ArrayView)
  
positive.code: 
  @pragma("vm:entry-point")
  class _Uint8ClampedList extends _TypedList
      with _IntListMixin<Uint8ClampedList>
      implements Uint8ClampedList {
    factory _Uint8ClampedList._uninstantiable() {
      throw "Unreachable";
  
negative.code: 
  @pragma("vm:entry-point")
  class _Float32List extends _TypedList
      with _DoubleListMixin, _TypedDoubleListMixin<Float32List>
      implements Float32List {
    factory _Float32List._uninstantiable() {
      throw "Unreachable";
  