Deprecate direct access to component's go/done interface

[rachitnigam]

Once #300 is merged, the default way to call a component will be the invoke statement. Once that is the case, we can change the ir::Builder so that it doesn't automatically add go/done ports to components (and move that functionality to component-interface pass).

Few things that rely on this interface:

• Systolic array generator (only use for mult_pipe in the default PE. Removable after Make primitives use invokable go-done interface #331).
• Relay
• Code generated by Dahlia for sqrt and mult_pipe (requires Make primitives use invokable go-done interface #331).

[rachitnigam]

Actually, I think the stuff above is irrelevant to deprecating accessing to the component go/done signal usage. Once #712 is merged, any group computation performed by a group using the a component's go/done interface can be rewritten using invoke-with.

I don't think there is any harm in keeping access to primitive's go/done ports either. Maybe we should remove this issue in lieu of having explicit go/done ports on all components.

[sampsyo]

Without thinking about it too hard, I'm inclined to agree? (That is, that there is no harm in keeping explicit access around & possible, especially if we require all components to have such ports.) It seems like this explicit access would nicely provide a "compile target" for invoke if I'm not mistaken, right?