fmpz_mpoly_factor_lcc_wang

Wang's leading coefficient determination [Wan1978]. Given the irreducible factorisation lcAfac of the leading coefficient of A in x_0 and the factorisation \mathit{Auc} \prod_{i < r} \mathit{Auf}_i of A(x_0, \alpha), sets lc_divs[i] to the predicted leading coefficient of the i-th factor of A: the product of the powers of the factors of the leading coefficient whose values at \alpha divide the leading coefficient of \mathit{Auf}_i, times an integer. Returns 0 if the evaluation point fails Wang's condition, that each factor of the leading coefficient evaluates to an integer with a prime divisor not dividing \mathit{Auc} times the constant and the values of the other factors.