PATCH commited to dataflow branch.

[Paolo Bonzini]

Kenneth Zadeck wrote:
> This patch contains code to detect auto-inc/dec instructions using df.
> The code is much more comprehensive about finding matches than the
> existing flow based code but it also the test to assure that such a
> change is not more expensive than leaving the code the way that it was. 

Cool.  Very cool.

A nit: could you please use subjects like "[dataflow, committed] Rewrite 
auto-inc/dec to use df, first set of ARM fixes"?

Thanks for all your work,

Paolo