Also moves passive RLC inference out from migration to just-in-time
creation for the simulator or netlisting.
Also fixes a version guard mismatch because the spice migration was
done inside UpdateSymbolInstances (which has its own version guard).
Also changed UpdateSymbolInstances to UpdateSymbolInstanceData so
someone else in the future doesn't think it's a general-purpose symbol
instance updater.
Jeff Young
Marek Roszko