Add new heuristic for resolving instruction sizes. Add new heuristic for resolving instruction sizes. This applies to the the decision between extended and base page addressing by calculating the range of possible addresses (if reasonably knowable) and deciding on whether to force extended addressing based on that. (If the whole range is outside the direct page, extended addressing is required.)

The lwbasic directory is an in-progress attempt to write a compiler for a
dialect of basic specifically targetted at the 6809 CPU. It is still
incomplete but is included in this distribution in case someone finds the
code useful. It is not built by default.