-primRepHint :: PrimRep -> MachHint
-primRepHint VoidRep = panic "primRepHint:VoidRep"
-primRepHint PtrRep = PtrHint
-primRepHint IntRep = SignedHint
-primRepHint WordRep = NoHint
-primRepHint Int64Rep = SignedHint
-primRepHint Word64Rep = NoHint
-primRepHint AddrRep = PtrHint -- NB! PtrHint, but NonPtrArg
-primRepHint FloatRep = FloatHint
-primRepHint DoubleRep = FloatHint
-