Internals: Add sameGateTree.
Fix not tracing modules following primitives, bug837.
Optimize e.g. {(b<<4)[7:4], (b<<4)[3:0]}. From assignmerge tree.

Signed-off-by: Wilson Snyder <wsnyder@wsnyder.org>
Add optimization of wires from arrayed cells, msg1447.

Signed-off-by: Wilson Snyder <wsnyder@wsnyder.org>
Fix trace overflow on huge arrays, bug834.
Fix public parameters in unused packages, bug804.
Add public enums, bug833.
Trace_off now operates on cells, bug826.