pprIfaceContext :: IfaceContext -> SDoc
-- Prints "(C a, D b) =>", including the arrow
pprIfaceContext [] = empty
-pprIfaceContext theta = ppr_preds theta <+> ptext (sLit "=>")
+pprIfaceContext theta = ppr_preds theta <+> darrow
ppr_preds :: [IfacePredType] -> SDoc
ppr_preds [pred] = ppr pred -- No parens