Make Node.nodes.insertAll take an end-positioned index.

tools/dom/templates/html/impl/impl_Node.darttemplate

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of $LIBRARYNAME;
 
 /**
  * Lazy implementation of the child nodes of an element that does not request
  * the actual child nodes of an element until strictly necessary greatly
  * improving performance for the typical cases where it is not required.
@@ skipping 65 matching lines @@
       throw new RangeError.range(index, 0, length);
     }
     if (index == length) {
       _this.append(node);
     } else {
       _this.insertBefore(node, this[index]);
     }
   }
 
   void insertAll(int index, Iterable<Node> iterable) {
-    var item = this[index];
-    _this.insertAllBefore(iterable, item);
+    if (index == length) {
+      addAll(iterable);
+    } else {
+      var item = this[index];
+      _this.insertAllBefore(iterable, item);
+    }
   }
 
   void setAll(int index, Iterable<Node> iterable) {
     throw new UnsupportedError("Cannot setAll on Node list");
   }
 
   Node removeLast() {
     final result = last;
     if (result != null) {
       _this._removeChild(result);
@@ skipping 166 matching lines @@
       _removeChild(firstChild);
     }
   }
 
   /**
    * Print out a String representation of this Node.
    */
   String toString() => nodeValue == null ? super.toString() : nodeValue;
 $!MEMBERS
 }