Implement intraprocedural dataflow for ipa-modref EAF analyser

[Jan Hubicka]

> On 11/4/21 15:12, Jan Hubicka via Gcc-patches wrote:
> > |Bootstrapped/regtested x86_64-linux, plan to commit after bit more testing.|
> 
> Can you please install the patch after the current MOD REF crashes are fixed?
> It will help us with the future bisection.

Sure, this is what I am doing today :)

Honza
> 
> Thanks,
> Martin