Change Link to List in FunctionSignature.

pkg/compiler/lib/src/util/link.dart

 // Copyright (c) 2011, 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.
 
 part of dart2js.util;
 
 class Link<T> {
   T get head => throw new StateError("no elements");
   Link<T> get tail => null;
 
@@ skipping 38 matching lines @@
       result = new List();
       result.length = slowLength();
     }
     int i = 0;
     for (Link<T> link = this; !link.isEmpty; link = link.tail) {
       result[i++] = fn(link.head);
     }
     return result;
   }
 
-  /// Invokes `fn` for every item in the linked list and returns the results
-  /// in a [Set].
-  Set mapToSet(dynamic fn(T item)) {
-    Set result = new Set();
-    for (Link<T> link = this; !link.isEmpty; link = link.tail) {
-      result.add(fn(link.head));
-    }
-    return result;
-  }
-
   bool get isEmpty => true;
 
   Link<T> reverse() => this;
 
   Link<T> reversePrependAll(Link<T> from) {
     if (from.isEmpty) return this;
     return this.prepend(from.head).reversePrependAll(from.tail);
   }
 
   Link<T> skip(int n) {
@@ skipping 61 matching lines @@
    */
   Link<T> toLink([Link<T> tail = const Link()]);
 
   List<T> toList();
 
   void addLast(T t);
 
   final int length;
   final bool isEmpty;
 }