Add List.insert.

runtime/lib/byte_array.dart

Index: runtime/lib/byte_array.dart
diff --git a/runtime/lib/byte_array.dart b/runtime/lib/byte_array.dart
index ef482858b8e13812afd4e23014ba5a8eaeb6ab05..172320171c8e5260f8d51eefe0c293a26e56d617 100644
--- a/runtime/lib/byte_array.dart
+++ b/runtime/lib/byte_array.dart
@@ -1991,6 +1991,11 @@ class _ByteArrayViewBase extends Collection<int> {
         "Cannot remove from a non-extendable array");
   }
 
+  void insertAt(int index, int element) {
+    throw new UnsupportedError(
+        "Cannot add to a non-extendable array");
+  }
+
   int removeAt(int index) {
     throw new UnsupportedError(
         "Cannot remove from a non-extendable array");