[C2hs] other c2hs patches

[John Lato]

Duncan, thanks for all your help recently.  I've got another question
that depends a bit on the recent patch I submitted.

The file Config.hs defines a value for cppopts that is something like
"-x c", varying on the platform.  If cpp is called using runProcess,
then (at least on Windows), those need to be passed as separate
arguments (i.e. ["-x", "c"]) in order for cpp to understand them.
Although it's a pretty simple change, is this true for other platforms
(e.g. Linux) as well?

Thanks,
John