fix(runtime): use more null proto objects (#23921)

This is a primordialization effort to improve resistance against users
tampering with the global `Object` prototype.

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index fcec6b91a..6e423af6b 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -252,7 +252,7 @@ function workerClose() {
   op_worker_close();
 }
 
-function postMessage(message, transferOrOptions = {}) {
+function postMessage(message, transferOrOptions = { __proto__: null }) {
   const prefix =
     "Failed to execute 'postMessage' on 'DedicatedWorkerGlobalScope'";
   webidl.requiredArguments(arguments.length, 1, prefix);