+
+-- XXX - 2006-09-24: This case is hard-coded in (rendering predicates opaque as well)
+-- to make the newly reworked newtype-deriving work on the trivial case:
+-- newtype T = T () deriving (Eq, Ord)
+-- Please remove this if the newtype-deriving scheme no longer produces a PredTy.
+tcSplitTyConApp_maybe (PredTy (ClassP _ [ty'])) = tcSplitTyConApp_maybe ty'
+