The goal here is to use as single ordering heuristic (which can be
improved later) within MTasks as we do for serial code ordering. The
heuristic itself is factored out into the new OrderMoveGraphSerializer.
This also yields slightly nicer ordering than the previously use
GraphStream, so we end up with fewer trigger (domain) conditionals in
the MTasks, this can be worth a few percent speedup.
This has the somewhat nice side-effect of reusing OrderMoveGraphVertex
for both serial and parallel mode, so MTaskMoveGraphVertex can be
removed.
Serial mode yields identical output.
Continuing the idea of decoupling the implementations of the various algorithms.
The main points:
-Move the former "processDomain" stuff, dealing with assigning combinational logic into the relevant sensitivity domains into V3OrderProcessDomains.cpp
-Move the parallel code construction in V3OrderParallel.cpp (Could combine this with some parts of V3Partition - those not called from V3Partition::finalize - but that's not for this patch).
-Move the serial code construction into V3OrderSerial.cpp
-Factored the very small common code between the parallel and serial code construction (processMoveOneLogic) into V3OrderCFuncEmitter.cpp
