Model Flags

[philzook58]

We're enforcing certain ordering constraints using a single "world" token that gets assigned to a dummy register. I hate this. We should be modelling flags which get preassigned to the appropriate flag "registers" for the minizinc model.

[philzook58]

Ok, hate is too strong. It is useful and appropriate sometimes. But not for modelling flags.

[codyroux]

Yea it's bogus for flags, but I was lazy. And it's good for some other things.

Part of the issue was that we weren't modelling flags in the C semantics, so there was a slight mismatch.

But mostly the lazy.