+
+-- Naked PredTys don't usually show up, but they can as a result of
+-- {-# SPECIALISE instance Ord Char #-}
+-- The Right Thing would be to fix the way that SPECIALISE instance pragmas
+-- are handled, but the quick thing is just to permit PredTys here.
+check_tau_type rank ubx_tup (PredTy sty) = getDOpts `thenM` \ dflags ->
+ check_source_ty dflags TypeCtxt sty