Haskell --cnf backend produces code with error: Illegal type synonym family application

With ghc-7.10, the code generated by the Haskell CNF backend does not compile:
```
$ bnfc --haskell --cnf -m Calc.cf 
...
$ make
```
yields
```
Compiling CnfTablesCalc    ( CnfTablesCalc.hs, CnfTablesCalc.o )

CnfTablesCalc.hs:14:10:
    Illegal type synonym family application in instance:
      [(CATEGORY, Any)]
    In the instance declaration for ‘RingP [(CATEGORY, Any)]’
```