This modifies function parameter passing to pass the counter
buffer associated with a struct buffer to a function as a
hidden parameter.  Similarly function declarations will have
hidden parameters added to accept the associated counter buffers.

There is a limitation: if a SB type may or may not have an associated
counter, passing it as a function parameter will assume that it does, and
the counter will appear in the linkage whether or not there is a counter
method used on the object.