[patch] Merge data dependence bits for interchanging swim loops

[Giovanni Bajo]

Sebastian Pop wrote:

> Here is the patch that merges from lno the data dependence analysis
> improvements that allow the validation of the loops interchange in the
> swim benchmark.
>
> Bootstrapped on i686-pc-linux-gnu with BOOT_CFLAGS='-g -O2
> -ftree-loop-linear' and tested.

Can you please test it on several different platforms? Even if this is an
exception, we are still in Stage 3, so stability is our first goal at this
point.

Giovanni Bajo