Fix annotation of generic method invocations in Fasta inference tests (again).

pkg/front_end/testcases/inference/generic_methods_iterable_and_future.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /*@testedFeatures=inference*/
 library test;
 
 import 'dart:async';
 
 Future<int> make(int x) => (new /*@typeArgs=int*/ Future(
@@ skipping 20 matching lines @@
                   '',
                   /*info:INFERRED_TYPE_CLOSURE,error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ /*@returnType=String*/ (String
                               x,
                           /*@type=int*/ y) =>
                       /*@promotedType=none*/ x + /*@promotedType=none*/ y
                           .toString()));
 
   Future<String> results4 = /*@promotedType=none*/ results
       . /*@typeArgs=String*/ then(
           /*@returnType=String*/ (List<int> list) => /*@promotedType=none*/ list
-              . /*@typeArgs=String*/ fold<String>(
+              .fold<String>(
                   '',
                   /*@returnType=String*/ (/*@type=String*/ x,
                           /*@type=int*/ y) =>
                       /*@promotedType=none*/ x + /*@promotedType=none*/ y
                           .toString()));
 }