Building Elfutils with Mingw32

[Ulf Hermann]

Indeed I have noticed the other patches, but I don't think they are the 
same as mine. So, now we have a three way merge.

I guess some more of the changes could be merged if properly cleaned up 
and made to benefit other obscure platforms, too. However, there are a 
few I got a definite "no" for. In particular the windows dance around 
text/binary mode when opening files was not welcome. I couldn't come up 
with a better solution than adding an O_BINARY or O_TEXT to every single 
open() call. We actually need the distinction as some files need to be 
opened in text mode for the tests to pass. If you can come up with 
anything better here, please let me know.

best regards,
Ulf