Included limits.h to resolve missing macro definition.

diff --git a/tools/bin2res.c b/tools/bin2res.c
index 9075839..e1654a3 100644
--- a/tools/bin2res.c
+++ b/tools/bin2res.c
@@ -28,6 +28,7 @@
 #include <ctype.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <limits.h>
 #ifdef HAVE_SYS_PARAM_H
 # include <sys/param.h>
 #endif