[patch v3] aligned_alloc: conform to C17

[Florian Weimer]

* DJ Delorie:

> Florian Weimer <fw@deneb.enyo.de> writes:
>> I'm surprised that this even compiles.  This sort of makes the
>> function static and gives it external linkage.
>
> It almost does the same thing as your example, but follows the
> internal/external paradigm we've been using for all the other functions.
>
> (in your example, just drop the "static", then it's the same)
>
> And yes, it took Carlos and I a while to go through all this linkage
> stuff to make sure we understood it.

Yeah, the static was wrong.  I think you should avoid the alias if
there aren't any internal calls.