mktime, timegm: share common declaration * lib/mktime-internal.h: New file. * lib/mktime.c: Use it rather than open-coding a declaration. * lib/timegm.c: Likewise. * modules/mktime (Files): Ship it. * modules/timegm (Files): Likewise. Suggested by Bruno Haible. Signed-off-by: Eric Blake <ebb9@byu.net>

+
−#include <time.h>
+
−time_t mktime_internal (struct tm *,
+
−                        struct tm * (*) (time_t const *, struct tm *),
+
−                        time_t *);