Added support for tracking which ConcreteRuntimeObjNodes can be Arrays and which can be array elements. Array elements get their own case statement since if we add the entire array into the queue, then it's probably better to let the switch statement handle what to do with objects from a specific allocation site.
I had more code written, but apparently my workspace was not up to date. The changes I made need changes, so I omitted them. It's okay since I need to ask Yonghun/Jim about arrays on the C-side anyway.