[RFC] [autovect patch] Implement vectorization hints

[Zdenek Dvorak]

Hello,

> > > Just FYI, xlc associates the info with the loop in a loop table (the
> > > frontend creates the initial loop table), and keeps the loop table up 
> > > to
> > > date forever onwards :)
> > 
> > But GCC does not keep up to date loop tables ;).
> 
> This won't change if everyone just keeps on doing other things instead
> of doing the work necessary to start this.

I will start working on that; as a first step, I will try to get
loop-aware cfg cleanup merged, rest of the tree loop optimization passes
should not be too problematic hopefully.

Zdenek