failtest: use 64 bit offsets if available.

We have to be consistent with the caller, so turn on 64 bit offsets if
available for both the caller and us.

ccan/failtest/failtest.c

 /* Licensed under LGPL - see LICENSE file for details */
-#include "config.h"
+#include <ccan/failtest/failtest.h>
 #include <stdarg.h>
 #include <string.h>
 #include <stdio.h>
@@ -17,7 +17,6 @@
 #include <assert.h>
 #include <ccan/read_write_all/read_write_all.h>
 #include <ccan/failtest/failtest_proto.h>
-#include <ccan/failtest/failtest.h>
 #include <ccan/build_assert/build_assert.h>
 
 enum failtest_result (*failtest_hook)(struct failtest_call *, unsigned);

ccan/failtest/failtest.h

@@ -2,6 +2,9 @@
 #ifndef CCAN_FAILTEST_H
 #define CCAN_FAILTEST_H
 #include "config.h"
+#if HAVE_FILE_OFFSET_BITS
+#define _FILE_OFFSET_BITS 64
+#endif
 #include <sys/types.h>
 #include <stdbool.h>
 #include <fcntl.h>

ccan/failtest/failtest_override.h

@@ -3,6 +3,9 @@
 #define CCAN_FAILTEST_OVERRIDE_H
 /* This file is included before the source file to test. */
 #include "config.h"
+#if HAVE_FILE_OFFSET_BITS
+#define _FILE_OFFSET_BITS 64
+#endif
 
 /* Replacement of allocators. */
 #include <stdlib.h>