[PATCH 12/23] nptl: Introduce __nptl_deferred_init

[Florian Weimer]

* Carlos O'Donell:

>> We don't really need in fact, pthread_cancel can call __pthread_exit
>> directly if the argument is THREAD_SELF. And with my canceltype and
>> cancelstate refactor we don't even need the whole atomic bit set
>> support.
>
> And POSIX in the RATIONALE says exactly this:
> ~~~
> The special function also means that implementations are not obliged
> to implement cancellation with signals.
> ~~~
> https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cancel.html

My question was whether we use the signal mask to block cancellation,
but I don't think that's the case (except in some cases where we block
*all* signals for other reasons).

But calling pthread_exit is probably not the right thing to do because
pthread_cancel is itself not a cancellation point.

In any case, I really don't want to change the implementation as part of
this series.

Thnaks,
Florian