[GHC] #2305: GHC does not care __RENAME macro

[Claus Reinke]

> I've augmented the Using-the-FFI page too.  I hope I got it right.
> 
> http://haskell.org/haskellwiki/GHC/Using_the_FFI#Importing_C_functions_that_turn_out_to_be_CPP_macros

hmm. and what if the CPP/C status of a function fluctuates
(different OS/library versions/..)? does the simple binding
then become an exorcise is autoconf? mingw, e.g., has had
a habit of being different there at times.

CPP is part of C (well, it was a long time ago, at least),
and those wrappers look like something that could and
should be automated, like other wrappers in the FFI.

perhaps ghc feeding those foreign imports to gcc, when
in doubt, and linking in the result?

claus