get strtoll on freebsd
diff --git a/include/u.h b/include/u.h
index 466f3ea..ac9699c 100644
--- a/include/u.h
+++ b/include/u.h
@@ -20,6 +20,14 @@
 #	define _XOPEN_SOURCE 1000
 #	define _XOPEN_SOURCE_EXTENDED 1
 #endif
+#if defined(__FreeBSD__)
+#	include <sys/cdefs.h>
+	/* for strtoll */
+#	undef __ISO_C_VISIBLE
+#	define __ISO_C_VISIBLE 1999
+#	undef __LONG_LONG_SUPPORTED
+#	define __LONG_LONG_SUPPORTED
+#endif
 #define _LARGEFILE64_SOURCE 1
 #define _FILE_OFFSET_BITS 64