OpenBSD does not expose vasprintf when _XOPEN_SOURCE is defined, but
__bsd_locale_fallbacks.h in the platform libc++ requires this to be
visible, thereby causing a compilation failure. In fact, strptime and
vasprintf are normally visible without defining any standard-visibility
#defines, so don't do anything special here.
OpenBSD does not expose
vasprintfwhen_XOPEN_SOURCEis defined, but__bsd_locale_fallbacks.hin the platform libc++ requires this to be visible, thereby causing a compilation failure. In fact,strptimeandvasprintfare normally visible without defining any standard-visibility#defines, so don't do anything special here.This change is