With _POSIX_PTHREAD_SEMANTICS or _POSIX_C_SOURCE defined
solaris cc uses the POSIX API for asctime_r, i.e. two args, not three.
In practice it is recommended not to use a buffer-overflow sensitive asctime at all, rather strftime.
gnulib disabled it already. wrong years can lead to overflows
Work in branch rurban/asctime_r-gh858
[GH #858] Fix solaris asctime_r with _POSIX_PTHREAD_SEMANTICS/_POSIX_…