Only merge domains that genuninely are together.

src:
	* V3Order.cpp (OrderVisitor::domainMatch): Deleted.
	(OrderVisitor::mergeDomains): Created.
	(OrderVisitor::mergeDomainsIterate): Created.
	(OrderVisitor::m_pvarrefp): Created.
	(OrderVisitor::processEdgeReport): Add string suffix argument
	(OrderVisitor::processDomains): Remove code putting gated domain
	into parent.
	(OrderVisitor::visit(AstNodeVarRef,...)): Set m_pvarrefp
	(OrderVisitor::process): call mergeDomains and add reports after.
	(OrderVisitor::OrderVisitor): Clear m_pvarrefp
	* Sentree.h (SenTreeFinder::getSenItem): Deleted.