[RFC][PATCH v2] Add reallocarray function.

[Paul Eggert]

Rich Felker wrote:
> Not really related to this patch, but I think the comment about
> __attribute_malloc__ that was copied from realloc is wrong. The new
> and old pointers cannot alias

You're correct that the new and old pointers cannot alias, but I fear 
that __attribute_malloc__ does not mean what you think it means.  The 
GCC documentation is *really* confusing in this area, unfortunately.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56955