[setup patch] Fix cygwin-mode compilation.

[Max Bowsher]

"Robert Collins" wrote:
> On Thu, 2003-01-16 at 04:13, Max Bowsher wrote:
>> It's occasionally useful to compile setup.exe linked with cygwin1.dll, to
>> debug a crash that occurs within msvcrt.dll.
>
> At first glance looks reasonable - have you tested this?
>
> If so, please commit.

Well, it compiles, which is better than it did before, and it runs too :-)
I haven't carefully verified the semantics, but since it's only #ifdefed in
for Cygwin-linked builds, I'm going to commit.

Max.