RFA: patch for usage of more accurate live information for the global and the reload.

[Daniel Berlin]

> Inefficient when number of basic blocks > 1000.  You know exactly
> how many blocks there are to begin.
>
> All the actual algorithm bits look good.
>
>

Except that i'm a bit curious why he wrote forward_propagate_solution 
instead of reusing the functions from df.c that do dataflow equation 
solving for bitmaps.


> r~