Yeah, that's very weird. I've tried Googling other "___ actors" to achieve similar results. "Gun actors" shows actors from the movie Gun and says "Actors > Gun" the way "shit actors" says "Actors > Shit". Others are either just regular results or something like "blade actors" which returns actors from Blade, except the header says "Blade > Cast".
There does not appear to be any production named Shit starring Louis C.K., Scarface and Donald Glover. I wonder if this is some renegade (and perhaps racist) Google employee having a laugh.
edit: "knife actors" has some odd results. Robert Aldrich, presumably for The Big Knife... Bobby Darin, "Mack the Knife" of course.