Include the compiler infrastructure to vhdlpp for collecting the
file and line information and attaching it to entities and ports.
Make the parser store the file name during parse.
Create a libmisc library where I can put source files that are
used by multiple programs within the source tree.
Add enough rules to parse a simple VHDL program:
Parse library and use clauses,
Parse entity declarations, and
Parse architecture bodies.
Add some parser infrastructure:
Handle syntax errors with useful error messages,
Include file name and line numbers in parse errors,
Add some parser debug aids.