[PATCH 3/6] nptl: Make pthread_kill async-signal-safe

[Florian Weimer]

* Adhemerval Zanella via Libc-alpha:

> Simiar to raise (BZ #15368), pthread_kill is also defined as
> async-signal-safe (POSIX.1-2008 TC1).  However, similar to raise
> it has the same issues relating to signal handling.
>
> Different than raise, all the signal are blocked so it would be
> possible to implement pthread_cancel (which also should be
> async-cancel safe).

What do you mean by implementing pthread_cancel?

Patch looks okay as far as I can see, but we'll eventually need a
different approach to deal with the TID reuse race.