MS-Windows build broken in Fmake_network_process

[Eli Zaretskii <eliz@gnu.org>]

This change:

    revno: 99750
    author: Helmut Eller <eller.helmut@gmail.com>
    committer: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
    branch nick: trunk
    timestamp: Thu 2010-03-25 17:48:52 +0900
    message:
      Call `select' for interrupted `connect' rather than creating new socket (Bug#5173).

breaks the MS-Windows build:

The compiler emits a warning, and the linker errors out:

  gcc -I. -c -gdwarf-2 -g3  -mtune=pentium4 -O2     -Demacs=1 -DHAVE_CONFIG_H -I../nt/inc -DHAVE_NTGUI=1 -DUSE_CRT_DLL=1 -o oo-spd/i386/process.o process.c
  process.c: In function `Fmake_network_process':
  process.c:3663: warning: passing arg 4 of `getsockopt' from incompatible pointer type

  oo-spd/i386/temacs1.a(process.o)(.text+0x3297): In function `Fmake_network_process':
  D:\gnu\bzr\emacs\trunk\src/process.c:3663: undefined reference to `getsockopt@20'

The compiler warning is because the prototype on Windows is:

  int getsockopt(SOCKET, int, int, char*, int*);

The linker error is because we would need to link against yet another
library to get this function.  But I don't think we should do that.
I'm actually bewildered why this code:

	    int len = sizeof xerrno;
	    eassert (FD_ISSET (s, &fdset));
	    if (getsockopt (s, SOL_SOCKET, SO_ERROR, &xerrno, &len) == -1)
	      report_file_error ("getsockopt failed", Qnil);

was used unconditionally when a very similar code in
wait_reading_process_output is clearly marked with a comment saying
not to use it except on GNU/Linux:

  #ifdef GNU_LINUX
		/* getsockopt(,,SO_ERROR,,) is said to hang on some systems.
		   So only use it on systems where it is known to work.  */
		{
		  int xlen = sizeof(xerrno);
		  if (getsockopt(channel, SOL_SOCKET, SO_ERROR, &xerrno, &xlen))
		    xerrno = errno;
		}
  #else

Would you please provide an alternative code (similar to what the
#else branch does in wait_reading_process_output) that will not use
getsockopt?