There is a version of the R-27 that is anti-radar, however an air-to-air anti-radar missile would only be usefull against "normal" radars.
The APG-77 functioning would render such missile useless and the reason is simple, it was designed to not give away the F-22´s position to the enemy, so, if even the RHAWS of the target aircraft can´t see that the aircraft is beeing painted, its not a missle with much less brains that is going to take the F-22 out of the sky.
I think that the only situation were an anti-radar missile shot at the F-22 is plausible is in a scenario that, in my opinion, is completly stupid, that is, the Raptor turning the radar on at max output to try to jam the enemy´s radar. That would certainly make the Raptor very visible, but, since the F-22 certainly has its own ECM gear and that i see no reason why he would try jam enemy radars with its own radar, making himself visible to the enemy, i think that its non-sense to talk about using air-to-air anti-radar missiles against the F-22.
I think that is much more plausible to invest in advanced IRST systems.