Use List instead of Link in the type system.

tests/compiler/dart2js/link_test.dart

Index: tests/compiler/dart2js/link_test.dart
diff --git a/tests/compiler/dart2js/link_test.dart b/tests/compiler/dart2js/link_test.dart
index 681c5ef78ac7a9dddbeb5b79d668821c3e2a3cd9..1096c60c55ec47552129024291740748af8f99ba 100644
--- a/tests/compiler/dart2js/link_test.dart
+++ b/tests/compiler/dart2js/link_test.dart
@@ -23,10 +23,6 @@ main() {
   testSkip();
 }
 
-testFromList(List list) {
-  test(new Link.fromList(list), list);
-}
-
 test(Link link, List list) {
   Expect.equals(list.isEmpty, link.isEmpty);
   int i = 0;
@@ -48,7 +44,7 @@ test(Link link, List list) {
 }
 
 testSkip() {
-  var nonEmptyLink = new Link.fromList([0, 1, 2, 3, 4, 5]);
+  var nonEmptyLink = LinkFromList([0, 1, 2, 3, 4, 5]);
   for (int i = 0 ; i < 5; i++) {
     var link = nonEmptyLink.skip(i);
     Expect.isFalse(link.isEmpty);