When emitting a logical device as part of a continuous assignment
we need to use the actual inputs (not the output). We also do not
need to emit anything if the nexus is NULL. Also skip logical gates
that have a local output since they are part of a continuous
assignment and the inputs to a logical gate can be an expression
so emit them as a continuous assignment.
This patch adds the following to the vlog95 converter.
Add support for emitting and calling UDPs.
Generate a UDP for a synthesized DFF.
Add the ability do emit a constant assigned to a net.
This patch moves the logic and lpm code to a new file. It refactors
the strength emitting routine and adds support for emitting the
standard tran style of gates.
Cary R