[PATCH] check_native: Get rid of alloca

[Florian Weimer]

* Adhemerval Zanella Netto:

> Should we remove the one use on sysdeps/posix/readv.c and
> sysdeps/posix/writev.c?  It is only used on Hurd (which I am not use
> if support cancellation), but it a precedent to other developers that
> __attribute__ ((cleanup)) might be used in other code.

Hurd supports cancellation.  I think it would make sense to replace
these instances of __attribute__ ((cleanup) with with the usual
cancellation handler macros (assuming that it works, it may need IS_IN
(libc) conditionals).

Thanks,
Florian