sysfatal is built for ape but argv0 and its external definition are missing.

Reference: /n/sources/patch/finish-sysfatal-4-ape
Date: Tue Jan 13 12:04:54 CET 2015
Signed-off-by: steve@quintile.net

--- /sys/src/ape/lib/9/mkfile	Tue Jan 13 12:03:09 2015
+++ /sys/src/ape/lib/9/mkfile	Tue Jan 13 12:03:06 2015
@@ -21,6 +21,8 @@
 	u32.$O\
 	u64.$O\
 	unmount.$O\
+	argv0.$O\
+
 
 </sys/src/cmd/mksyslib
 
--- /sys/src/ape/lib/9/argv0.c	Thu Jan  1 00:00:00 1970
+++ /sys/src/ape/lib/9/argv0.c	Tue Jan 13 12:03:12 2015
@@ -0,0 +1 @@
+char *argv0;
--- /sys/include/ape/lib9.h	Tue Jan 13 12:03:18 2015
+++ /sys/include/ape/lib9.h	Tue Jan 13 12:03:15 2015
@@ -59,6 +59,7 @@
 
 #define	ARGC()		_argc
 
+extern	void	sysfatal(char *, ...);
 extern	int	errstr(char*, unsigned int);
 extern	int	bind(char*, char*, int);
 extern	int	mount(int, int, char*, int, char*);