Annotate another two ephemeral classes.

lib/elements/array-selector.html

@@ -348,6 +348,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
    * @constructor
    * @extends {Polymer.Element}
    * @implements {Polymer_ArraySelectorMixin}
+   * @private
    */
   let baseArraySelector = ArraySelectorMixin(Polymer.Element);
 

lib/utils/templatize.html

@@ -63,6 +63,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
      * Base class for TemplateInstance.
      * @constructor
      * @implements {Polymer_PropertyEffects}
+     * @private
      */
     const base = Polymer.PropertyEffects(class {});