While manually dumping signals with a macro works OK for standalone
modules, it doesn't work when multiple modules are included. Instead,
create a second top-level module to dump signals. Inspired (once again)
by [1].
[1] https://github.com/steveicarus/iverilog/issues/376#issuecomment-709907692
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Sean Anderson