public void addVirtualFunctionTablePointer(Pointer ptrType, int offset) {
		vftPtrTypeByOffset.put((long) offset, ptrType);
	}
Method for user to specify a location and type of a virtual function table pointer (from PDB)
@param ptrType the pointer data type
@param offset the offset
Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/pdbapplicator/CppCompositeType.java