The issue was that the types analysis was osr-aware, where
we would only type-analyze the sections of the function
accessible from the osr entry point.  The phi and definedness
analyses were not osr-aware, so they would think that phis
in certain places where the type analysis knew that they
were undefined.

So this change makes definedness and phi analysis osr-aware,
where they only analyze the appropriate section of the function.
I think this means that we will do these analyses more, since we
have to rerun them for each entry point, so hopefully analysis time
doesn't increase too much.