Method processMultiplier

Count the number of terms in the expression making up \b vn. If there are more than \b max terms, mark \b vn as \e explicit. The given Varnode is already assumed to have multiple descendants. We do a depth first traversal along op inputs, to recursively calculate the number of explicit terms in an expression. \param vn is the given Varnode \param max is the maximum number of terms to allow