[PATCH v2][BZ #13065] New pthread_barrier algorithm to fulfill barrier destruction requirements.

[Roland McGrath]

> ... here.  I've kept this for now -- do you want me to give all the
> barrier tests a one-line description in the first line (in a follow-up
> patch)?

It is a style requirement for all new source files added to libc that
the top line be a descriptive comment.  Do not commit any new files
that do not conform to this requirement.