[early patch] Speed up decl chaining

[Rafael Espíndola]

On 19 October 2013 02:30, Chandler Carruth <chandlerc at google.com> wrote:
> On Fri, Oct 18, 2013 at 9:24 PM, Rafael Espíndola
> <rafael.espindola at gmail.com> wrote:
>>
>> > What about just storing both the first and the last and keeping the
>> > direction as it is now?
>>
>> Storing it where?
>
>
> Uh, yea. Ignore me. ;]
>
> The other solution of course is to not make it a circular list, but I assume
> there is a good reason for doing that?

I *assumed* the same. We have methods for finding the most recent decl
and do use them, but I haven't checked if they can be replaced with
something else.

Cheers,
Rafael