anchor.diff:        if (source != null && allIndexed && typeVariables.isEmpty) {
           copyRuntimeTypeInfo(source, newObject);
         } else {
  -        callSetRuntimeTypeInfo(classElement, typeArguments, newObject);
  +        newObject =
  +            callSetRuntimeTypeInfo(classElement, typeArguments, newObject);
         }
       }
   
  
positive.code:   void pushWithPosition(HInstruction instruction, Node node) {
      push(attachPosition(instruction, node));
    }
  
    HInstruction peek() => stack.last;
  
    HInstruction pop() {
      return stack.removeLast();
  
negative.code:         return inferred.containsAll(compiler)
              ? backend.fixedArrayType
              : inferred;
        } else if (isGrowableListConstructorCall) {
          TypeMask inferred =
              TypeMaskFactory.inferredForNode(currentElement, send, compiler);
          return inferred.containsAll(compiler)
  