iselect.c followup

[Bill Schottstaedt]

Just in case the blizzard of stuff in the Mac OSX message
obscured a simple bugfix:

in iselect.c the HAVE_UNISTD_H macro is used before
it has any chance to be defined.  The code should be
something like:

#include "libguile/_scm.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "libguile/async.h"
#include "libguile/iselect.h"


I notice the same problem in coop.c.


(And to answer my own question in that post; yes "-all_load" needs to
be added to CFLAGS to use AC_CHECK_LIB with Guile 1.7.0 in Mac OSX).