sha1dc/sha1.c wanted to check the endianness of the target platform
at compilation time and used a CPP macro with a rather overly
generic name, "BIGENDIAN", to pass the result of the check around
in the file. It wasn't prepared for the same macro set to 0
(false) by the platform to signal that the target is _not_ a big
endian box, and assumed that the endianness detection logic it has
alone would be the one that is setting the macro, resulting in a
breakage on Windows. This has been fixed by using a bit less
generic name for the same purpose.