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 d75a60569480c775bb6dab8ef2bd758274216f29..4c0f91d150795a1c519100fc9cbdbb61506264ea 100644
--- a/tests/compiler/dart2js/resolver_test.dart
+++ b/tests/compiler/dart2js/resolver_test.dart
@@ -12,6 +12,7 @@ import "compiler_helper.dart";
 import "parser_helper.dart";
 
 import '../../../sdk/lib/_internal/compiler/implementation/dart_types.dart';
+import 'link_helper.dart';
 
 Node buildIdentifier(String name) => new Identifier(scan(name));
 
@@ -20,7 +21,7 @@ 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];
@@ -30,7 +31,7 @@ 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);
 }
 
@@ -128,14 +129,12 @@ testTypeVariables() {
     visitor.visit(definition.type);
     InterfaceType type = visitor.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);
   }