Depends-on:
sys_ioctl
-sys_socket
-errno
-fd-hook
+sys_socket [test "$ac_cv_header_winsock2_h" = yes || test $REPLACE_IOCTL = 1]
+errno [test "$ac_cv_header_winsock2_h" = yes || test $REPLACE_IOCTL = 1]
+fd-hook [test "$ac_cv_header_winsock2_h" = yes || test $REPLACE_IOCTL = 1]
configure.ac:
gl_FUNC_IOCTL