[patch 1/3] Sort du_head list and restrict register class by PREFERRED_RENAME_CLASS

[Paolo Bonzini]

Looks good, but I cannot approve it.

There are only a couple of extra braces.  You don't need to resend it, a 
reviewer will assume you fix it before committing:

> +  for (i = 0; i<  current_length; i++)
> +    {
> +      right = right->next_chain;
> +      if (right == NULL)
> +	{
> +	  return NULL;
> +	}
> +    }

... and ...

> +      while ((last_tail = merge(segment, current_length, cmp))
> +	     != NULL)
> +	{
> +	  segment =&last_tail->next_chain;
> +	}

... here.

BTW the two PREFERRED_RENAME_CLASS patches can be merged into one, I think.

Paolo