Just as visions of The Walkin’ Dude sent Captain Trips survivors on a pilgrimage to Vegas, Alexander Skarsgård playing Randall Flagg feels like something I dreamed into existence. I mean, on the one hand, Skarsgård is way too hot to be playing Flagg — he’s supposed to be charming, not a total babe — and on the other hand, I super don’t care. Whoopi Gold…