[cvs-nhc98] parse errors with where and explicit layout

[Malcolm Wallace]

> The module
>     module Q where
>     f = 3
>         where {
>             a = 3;
>         }
> gives me
>     5:7 Found _where_ but expected a {-end-of-definition-or-EOF-}

The trailing semicolon at the end of the _where_ block is not permitted
by Haskell'98  (I think - it isn't easy to find in the Report!). 

Regards,
    Malcolm