Get rid of promotedType=none annotations

pkg/front_end/testcases/inference/downward_inference_miscellaneous.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;
 
 typedef T Function2<S, T>(S x);
 
 class A<T> {
   Function2<T, T> x;
   A(this.x);
 }
 
 void main() {
   {
     // Variables, nested literals
     var /*@type=String*/ x = "hello";
     var /*@type=int*/ y = 3;
     void f(List<Map<int, String>> l) {}
     ;
     f(/*@typeArgs=Map<int, String>*/ [
-      /*@typeArgs=int, String*/ {
-        /*@promotedType=none*/ y: /*@promotedType=none*/ x
-      }
+      /*@typeArgs=int, String*/ {y: x}
     ]);
   }
   {
     int f(int x) => 0;
     A<int> a = new /*@typeArgs=int*/ A(f);
   }
 }