Don't index 'undefined' nodes generated from default parameters trans…

…pilation.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=208266009

src/com/google/javascript/jscomp/Es6RewriteDestructuring.java

@@ -726,6 +726,8 @@ private void visitDestructuringPatternInCatch(NodeTraversal t, Node pattern) {
    * Helper for transpiling DEFAULT_VALUE trees.
    */
   private static Node defaultValueHook(Node getprop, Node defaultValue) {
-    return IR.hook(IR.sheq(getprop, IR.name("undefined")), defaultValue, getprop.cloneTree());
+    Node undefined = IR.name("undefined");
+    undefined.makeNonIndexable();
+    return IR.hook(IR.sheq(getprop, undefined), defaultValue, getprop.cloneTree());
   }
 }