\brief Test if the given trial Varnode is likely only used for parameter passing Flow is followed from the Varnode itself and from ancestors the Varnode was copied from to see if it hits anything other than the given CALL or RETURN operation. \param maxlevel is the maximum number of times to recurse through ancestor copies \param invn is the given trial Varnode to test \param op is the given CALL
source not stored for this graph (policy: none)