What happens if the answer is yes? There are reports floating around that the Russians had shot down an F-117 in the late 90's during the Yugoslavian civil war. Of course, they’re unconfirmed.
First of all, with Syria practically on the Russian border, being invited in by the Syrians, and sharing a mutual defense pact, they have every right to enforce a NO-FLY ZONE and we don’t, especially since we arm, train, fund, and protect ISIS, or at least we did in earlier stages.
I think it’s a fool’s errand to send in F-22's and F-35's even if they successfully evade Russian air defenses because it gives the Russians the opportunity to learn the electronic signatures of these aircraft in order to rapidly develop counter-measures. Underestimating current capabilities of the Russians as well as real time adaptations of their war machine will prove costly and deadly.
But hell, our leaders will do it anyways because they’re drunk on hubris, chutzpah, and the blood of the innocents!