Use List instead of Link in the type system.

tests/compiler/dart2js/resolver_test.dart

Index: tests/compiler/dart2js/resolver_test.dart
diff --git a/tests/compiler/dart2js/resolver_test.dart b/tests/compiler/dart2js/resolver_test.dart
index 3107d36f66d554c0eabd7db7079e660677c183d2..e4bb95e2c963d03466c04b614e25bbfabe572da9 100644
--- a/tests/compiler/dart2js/resolver_test.dart
+++ b/tests/compiler/dart2js/resolver_test.dart
@@ -13,6 +13,7 @@ import "parser_helper.dart";
 
 import 'package:compiler/implementation/dart_types.dart';
 import 'package:compiler/implementation/elements/modelx.dart';
+import 'link_helper.dart';
 
 Node buildIdentifier(String name) => new Identifier(scan(name));
 
@@ -21,7 +22,7 @@ Node buildInitialization(String name) =>
       (parser, tokens) => parser.parseOptionallyInitializedIdentifier(tokens));
 
 createLocals(List variables) {
-  var locals = [];
+  var locals = <Node>[];
   for (final variable in variables) {
     String name = variable[0];
     bool init = variable[1];
@@ -31,7 +32,7 @@ createLocals(List variables) {
       locals.add(buildIdentifier(name));
     }
   }
-  var definitions = new NodeList(null, new Link.fromList(locals), null, null);
+  var definitions = new NodeList(null, LinkFromList(locals), null, null);
   return new VariableDefinitions(null, Modifiers.EMPTY, definitions);
 }
 
@@ -134,14 +135,12 @@ Future testTypeVariables() {
     visitor.visit(definition.type);
     InterfaceType type = visitor.registry.mapping.getType(definition.type);
     Expect.equals(definition.type.typeArguments.slowLength(),
-                  length(type.typeArguments));
+                  type.typeArguments.length);
     int index = 0;
-    Link<DartType> arguments = type.typeArguments;
-    while (!arguments.isEmpty) {
+    for (DartType argument in type.typeArguments) {
       Expect.equals(true, index < expectedElements.length);
-      Expect.equals(expectedElements[index], arguments.head.element);
+      Expect.equals(expectedElements[index], argument.element);
       index++;
-      arguments = arguments.tail;
     }
     Expect.equals(index, expectedElements.length);
   }