public Map<Address, Set<Address>> findTypeinfoRefsPossiblyInVtables(List<GccTypeinfo> typeinfos)
			throws CancelledException {

		Map<Address, Set<Address>> typeinfoRefMap = new HashMap<Address, Set<Address>>();

		for (GccTypeinfo typeinfo : typeinfos) {
			monitor.checkCancelled();

			Set<Address> typeinfoRefs = findTypeinfoRefsPossiblyInVtables(typeinfo);

			// don't add if no refs in possible vtables
			if (typeinfoRefs.isEmpty()) {
				continue;
			}
			typeinfoRefMap.put(typeinfo.getAddress(), typeinfoRefs);
		}
		return typeinfoRefMap;
	}
Method to find references to the given typeinfos that are possibly ref'd by
vtables (ie not in functions, other data, etc... and create a map
typeinfoAddress to Set<Address> refs possibly in vtable

@param typeinfos list of GccTypeinfo's
@return map
@throws CancelledException
Ghidra/Features/Decompiler/ghidra_scripts/classrecovery/RTTIGccClassRecoverer.java