Add some missing includes to kill warnings when building with the default
Config.h and using gcc's -fno-builtin. There are probably other files
with the similar problems.
Also, if building against uClibc, don't include asm/unistd.h in syscalls.c
and module_syscalls.c.
diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index 24bdf90..c79fbeb 100644
--- a/libbb/copy_file.c
+++ b/libbb/copy_file.c
@@ -29,6 +29,7 @@
#include <errno.h>
#include <dirent.h>
#include <stdlib.h>
+#include <string.h>
#include "libbb.h"