simplify inclusion of system header files.

diff --git a/index-pack.c b/index-pack.c
index c05feae16172ab4bae73cb5b2501dfde418ad5d8..43e007f8238006313e95b7d386a590ce51144dfa 100644 (file)
--- a/index-pack.c
+++ b/index-pack.c
@@ -1,8 +1,3 @@
-#define _XOPEN_SOURCE 600
-#include <unistd.h>
-#include <sys/time.h>
-#include <signal.h>
-
 #include "cache.h"
 #include "delta.h"
 #include "pack.h"