Use List instead of Link in the type system.

sdk/lib/_internal/compiler/implementation/native_handler.dart

 // Copyright (c) 2012, 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.
 
 library native;
 
 import 'dart:collection' show Queue;
 import 'dart2jslib.dart';
 import 'dart_types.dart';
 import 'elements/elements.dart';
@@ skipping 928 matching lines @@
 
   /// Models the behavior of having intances of [type] escape from Dart code
   /// into native code.
   void _escape(DartType type, Compiler compiler) {
     type = type.unalias(compiler);
     if (type is FunctionType) {
       FunctionType functionType = type;
       // A function might be called from native code, passing us novel
       // parameters.
       _escape(functionType.returnType, compiler);
-      for (Link<DartType> parameters = functionType.parameterTypes;
-           !parameters.isEmpty;
-           parameters = parameters.tail) {
-        _capture(parameters.head, compiler);
+      for (DartType parameter in functionType.parameterTypes) {
+        _capture(parameter, compiler);
       }
     }
   }
 
   /// Models the behavior of Dart code receiving instances and methods of [type]
   /// from native code.  We usually start the analysis by capturing a native
   /// method that has been used.
   void _capture(DartType type, Compiler compiler) {
     type = type.unalias(compiler);
     if (type is FunctionType) {
       FunctionType functionType = type;
       _capture(functionType.returnType, compiler);
-      for (Link<DartType> parameters = functionType.parameterTypes;
-           !parameters.isEmpty;
-           parameters = parameters.tail) {
-        _escape(parameters.head, compiler);
+      for (DartType parameter in functionType.parameterTypes) {
+        _escape(parameter, compiler);
       }
     } else {
       typesInstantiated.add(type);
     }
   }
 
   static _parseType(String typeString, Compiler compiler,
       lookup(name), locationNodeOrElement) {
     if (typeString == '=Object') return SpecialType.JsObject;
     if (typeString == 'dynamic') {
@@ skipping 214 matching lines @@
     LiteralString jsCode = nativeBody.asLiteralString();
     builder.push(new HForeign.statement(
         js.js.statementTemplateYielding(
             new js.LiteralStatement(jsCode.dartString.slowToString())),
         <HInstruction>[],
         new SideEffects(),
         null,
         backend.dynamicType));
   }
 }