nstrftime,time_rz: don’t depend on tzname * lib/strftime.c (HAVE_TZNAME_ARRAY) [_LIBC]: Remove. All uses removed. (__strftime_internal): Simplify calculation of zone to be closer to what glibc does. However, in Gnulib do not look at tzname as this is problematic for all the usual reasons; instead, use the underlying strftime with %Z, making sure that call to the underlying strftime is now always compiled in the non-glibc case. Set and revert TZ as needed around the underlying call. * lib/time-internal.h (struct tm_zone) [HAVE_TZNAME_ARRAY && !HAVE_STRUCT_TM_TM_ZONE]: Remove tzname_copy. All uses removed. (set_tz, revert_tz): Declare, as they’re now extern. (local_tz): Move here from time_rz.c, and now a macro. * lib/time_rz.c (save_abbr): Do not worry about tzname_copy, since strftime.c no longer needs it. Instead, save abbrs only from tm_zone. * modules/c-nstrftime, modules/nstrftime, modules/time_rz: (Depends-on): Remove tzname.