Re: scratch/accurate-warning-pos: Solid progress: the branch now bootstraps.

[Paul Eggert]

Stefan Monnier wrote:
> If we only do it for cons cells, then we don't need hashing: we can make
> "fat-cons-cells" which contain extra position info after car/cdr.

Yes, that's basically what I was proposing. Also, we'd probably need a boolean 
flag in each struct cons_block so that C (or maybe Lisp) code can quickly 
distinguish between a fat pair and a thin (normal) one, which should also be 
cheap and easy to do. (Not that I'm volunteering to do it right now....)