Chapter 8, Indirect and Special Wastes, does not clearly state whether or not a floor sink can be used as a waste receptor, Chapter 2, Definitions, does not define a waste receptor. The janitor's sinks that I have installed do have a removable strainer or basket, which is one of the stipulations for a waste receptor in Chapter 8.
So, while I am not the code authority in your or any other area, I would say yes, and be prepared to argue with the inspector on that point. I don't see where the sink being used for a janitor's sink has any bearing on whether or not it can serve as a waste receptor.