AccessorROfloat

[Anjiang-Wei]

https://github.com/StanfordLegion/legion-manual/blob/master/regions.tex#L185:
There are many accessor constructors pre-defined for different combinations of privileges and field types. For example, a `AccessorROfloat` is the type of an accessor with read-only privileges on a field of type `float`.

However, I don't think AccessorROfloat exists in Legion's header files.
The following code exists in circuit example's header file:
https://github.com/StanfordLegion/legion/blob/stable/examples/circuit/circuit.h#L85

typedef FieldAccessor<READ_ONLY,float,1,coord_t,Realm::AffineAccessor<float,1,coord_t> > AccessorROfloat;

I assume AccessorROfloat might not be something directly supported by Legion. If Legion internally supported AccessorROfloat, then there would be no need to use typedef in the circuit example.

[elliottslaughter]

I believe this is correct. Legion does not pre-define AccessorROfloat, nor do I think it would be good for it to do so.