[PATCH 2/2] posix: Correctly block/unblock all signals on Linux posix_spawn

[Florian Weimer]

* Adhemerval Zanella:

> This patch correctly block and unblocks all signals when executing
> Linux posix_spawn by using the __libc_signal_{un}block_all functions
> instead of default sigprocmask.  The latter might remove both
> SIGCANCEL and SIGSETXID from the blocked signal list.
>
> Checked on x86_64, i686, powerpc64le, and aarch64.
>
> 	* sysdeps/unix/sysv/linux/spawni.c (__spawnix): Correctly block and unblock
> 	all signals when executing the clone vfork child.
> 	(SIGALL_SET): Remove macro.

Looks good to me.  Thanks.