shutdown(3SOCKET) requires sys/socket.h

diff -wpruN --no-dereference '--exclude=*.orig' a~/src/util/peekfd.c a/src/util/peekfd.c
--- a~/src/util/peekfd.c	1970-01-01 00:00:00
+++ a/src/util/peekfd.c	1970-01-01 00:00:00
@@ -46,6 +46,9 @@
 #include <termios.h>
 #endif
 #include <unistd.h>
+#ifdef __illumos__
+#include <sys/socket.h>
+#endif
 
 #ifndef SHUT_RDWR
 #define SHUT_RDWR  2