Fix funResultTy so @funResultTy ANY _ = ANY@.

Without this patch `funResTy` would refuse to return a useful type when given

    Prelude Data.Rank1Typeable> funResultTy (typeOf (undefined :: ANY)) (typeOf (id :: ANY -> ANY))
    Left "ANY is not a function"

After the patch

    Prelude Data.Rank1Typeable> funResultTy (typeOf (undefined :: ANY)) (typeOf (id :: ANY -> ANY))
    Right ANY

which corresponds to what is obtained when inferring types for `undefined id`

    Prelude> :t undefined id
    undefined id :: t