Change new List(n) to return fixed length list.

runtime/lib/array.dart

Index: runtime/lib/array.dart
diff --git a/runtime/lib/array.dart b/runtime/lib/array.dart
index 1441dc2a50e4b34a97de693994693f7f365f85ea..fa47027984ba7cd29b9356171f4851309cbbb3fc 100644
--- a/runtime/lib/array.dart
+++ b/runtime/lib/array.dart
@@ -228,8 +228,8 @@ class _ObjectArray<E> implements List<E> {
 
   E max([int compare(E a, E b)]) => IterableMixinWorkaround.max(this, compare);
 
-  List<E> toList() {
-    return new List<E>.from(this);
+  List<E> toList({ bool growable: false}) {
+    return new List<E>.from(this, growable: growable);
   }
 
   Set<E> toSet() {
@@ -467,8 +467,8 @@ class _ImmutableArray<E> implements List<E> {
 
   E max([int compare(E a, E b)]) => IterableMixinWorkaround.max(this, compare);
 
-  List<E> toList() {
-    return new List<E>.from(this);
+  List<E> toList({ bool growable: false }) {
+    return new List<E>.from(this, growable: growable);
   }
 
   Set<E> toSet() {