Function wait_for_all 

fn wait_for_all(
    cx: &mut CurrentRealm<'_>,
    global: &GlobalScope,
    promises: Vec<Rc<Promise>>,
    success_steps: Rc<dyn Fn(&mut JSContext, Vec<HandleValue<'_>>)>,
    failure_steps: Rc<dyn Fn(&mut JSContext, HandleValue<'_>)>,
)

https://webidl.spec.whatwg.org/#wait-for-all