Header changes mostly, see comments

Updated a bunch of headers.
Right now, (o instanceof Object[]) doesn’t affect what the maximum
array dimension used in the program is. Should it? Other places where
types are used?
I tried it out to see what it would do, It doesn’t seem to affect the
runnability of our Mips. Not sure what it is getting for an index into
the class name table at compile time for Object[].