[patch] Reduce ridiculous stack use in _dl_map_object_deps

[Roland McGrath]

> +	{
> +	  size_t new_size;
> +
> +	  /* 16-align so extend_alloca has a chance to re-use the space.
> +	     Note that extend_alloca is broken for recent versions of GCC
> +	     on x86: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50938  */
> +	  new_size = (l->l_ldnum * sizeof (struct link_map *) + 15) & ~15;

Use an initialized defn.

> +	  if (new_size > needed_space_bytes)
> +	    needed_space
> +	      = extend_alloca (needed_space, needed_space_bytes, new_size);
> +
> +	  needed = needed_space;

Something has to update needed_space_bytes.