Bug 469625 - Deoptimize special own-properties, r=brendan.

js/src/jsarray.cpp

@@ -833,8 +833,6 @@ array_defineProperty(JSContext *cx, JSObject *obj, jsid id, jsval value,
     if (!isIndex || attrs != JSPROP_ENUMERATE) {
         if (!ENSURE_SLOW_ARRAY(cx, obj))
             return JS_FALSE;
-        if (isIndex && STOBJ_IS_DELEGATE(obj))
-            cx->runtime->anyArrayProtoHasElement = JS_TRUE;
         return js_DefineProperty(cx, obj, id, value, getter, setter, attrs, propp);
     }