gpgscm: Incorporate changes from GnuPG.
* gpgscm/scheme.c [__GNUC__] (type_to_string): Use __builtin_unreachable for GCC. * gpgscm/ffi.c (do_get_temp_path): Remove the last backslash. * gpgscm/ffi.c (do_chdir): Use gpg_error_from_syserror.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>