Re: tsleep(9): add global "nowake" channel

[Theo de Raadt]

I agree.  This chunk below is really gross and does not follow the
special wakeup channel metaphor.

It is *entirely clear* that a &channel called "nowake" has no wakeup.
Like duh.

> +/*
> + * nowake is a global sleep channel for threads that do not want
> + * to receive wakeup(9) broadcasts.
> + */
> +int __nowake;
> +void *nowake = &__nowake;