[i386] Replace builtins with vector extensions

[Marc Glisse]

On Thu, 9 Oct 2014, Uros Bizjak wrote:

> Given that this will be a substantial work and considering the request
> from Kirill, what do you think about separate development branch until
> AVXn stuff is finished? This will give a couple of weeks and a
> playground to finalize the approach for the conversion. Maybe even ada
> can be tested there to not regress with the compatibility stuff.

No problem. We can also wait until next stage1 if you believe the release 
of gcc-5 is too close.

-- 
Marc Glisse