add sysexits.h legacy header

include/sysexits.h

@@ -0,0 +1,21 @@
+#ifndef	_SYSEXITS_H
+#define _SYSEXITS_H
+#define EX_OK 0
+#define EX__BASE 64
+#define EX_USAGE 64
+#define EX_DATAERR 65
+#define EX_NOINPUT 66
+#define EX_NOUSER 67
+#define EX_NOHOST 68
+#define EX_UNAVAILABLE 69
+#define EX_SOFTWARE 70
+#define EX_OSERR 71
+#define EX_OSFILE 72
+#define EX_CANTCREAT 73
+#define EX_IOERR 74
+#define EX_TEMPFAIL 75
+#define EX_PROTOCOL 76
+#define EX_NOPERM 77
+#define EX_CONFIG 78
+#define EX__MAX 78
+#endif