Include sys/wait.h.

[HAVE_PTY_H]; Include pty.h.

src/process.c

@@ -102,6 +102,10 @@ Boston, MA 02111-1307, USA.  */
 #ifdef IRIS
 #include <sys/sysmacros.h>	/* for "minor" */
 #endif /* not IRIS */
+  
+#ifdef HAVE_SYS_WAIT
+#include <sys/wait.h>
+#endif
 
 #include "systime.h"
 #include "systty.h"
@@ -330,6 +334,9 @@ static int pty_max_bytes;
 extern Lisp_Object Vfile_name_coding_system, Vdefault_file_name_coding_system;
 
 #ifdef HAVE_PTYS
+#ifdef HAVE_PTY_H
+#include <pty.h>
+#endif
 /* The file name of the pty opened by allocate_pty.  */
 
 static char pty_name[24];