anchor.diff:            next.knownType = next.instructionType = newType;
             addDependentInstructionsToWorkList(next);
           }
  -        _validTargetClasses[next] = classes;
  -      } else if (newType != receiverType || !classes.treatAsDynamic) {
  +      } else if (newType != receiverType) {
           // Insert a refinement node after the call and update all
           // users dominated by the call to use that node instead of
           // [receiver].
  
positive.code:         instruction.block.addBefore(instruction.next, converted);
          receiver.replaceAllUsersDominatedBy(converted.next, converted);
          addDependentInstructionsToWorkList(converted);
          _validTargetClasses[converted] = classes;
        }
      }
  
  
negative.code:         instruction, compiler);
    }
  }
  