White space in ccall impents

[Alastair Reid]

> token -> special | "&" | fname | cid | whitespace
> special -> "static" | "dynamic" | "wrapper"
> fname -> ... ".h"              (... as I don't have [3] handy)
> cid -> ... excluding special   (... as I don't have [3] handy)
> whitespace -> { ' ' | '\t' }

For what it's worth, Hugs uses 'any non-empty sequence of non-space
characters' where you use '...' and uses different but probably
equivalent contortions where you use specials.

The practical difference from this is that Hugs would probably let you
foreign import things called 'foo[42]' if you wanted.  I guess this is not
what the ffi report intends :-)

--
Alastair