anchor.diff:    }
   
     Type visitLoop(Loop node) {
  -    fail(node, 'internal error');
  +    return unhandledStatement();
     }
   
     Type lookupMethodType(Node node, ClassElement classElement,
  
positive.code:       fail(selector, 'unexpected operator ${name}');
  
      } else if (node.isPropertyAccess) {
        if (node.receiver !== null) fail(node, 'cannot handle fields');
        Element element = elements[node];
        if (element === null) fail(node.selector, 'unresolved property');
        return computeType(element);
  
      } else if (node.isFunctionObjectInvocation) {
  
negative.code:     compiler.reportWarning(node, new TypeWarning(kind, arguments));
    }
  
    // TODO(karlklose): remove these functions.
    Type unhandledStatement() => StatementType.NOT_RETURNING;
    Type unhandledExpression() => types.dynamicType;
  
    Type analyzeNonVoid(Node node) {
      Type type = analyze(node);
      if (type == types.voidType) {
  