When a signal (or port) is assigned by a sequential assignment,
the signal or port becomes a reg, instead of a wire(net). Detect
this distinction during elaboration and generate the correct
signal/port declaration.
Keep the entity/component/module port declarations in the module port
list of the generated code. This clarifies the generated code and
fixes a couple bugs for more complicated types.
These signals are declared in the architecture and are local to
the module. The Architecture already parsed and stored these signal
declarations, but this patch adds the ability to actually emit these
signals in the generated code.
In the process of doing this, I had to regularize the elaboration
and emit of VTypes, so that it can be used in multiple places, not
just in entity headers (for ports).
I also added support for bit selects of signals. This effected a couple
places in the parser, and expressions in general.
These go into the architecture/block of their scope and will be
used by component instantiations to make sure the bindings are
correct and complete.
Also handle signal declarations. The elaborator will use these
to generate module local variables that are used by the architecture.
Stephen Williams