message: fml preprocessing: skip generating fmls of disabled types (undef/poison input)
  this could be a correctness issue if we end up with an undef fml == poison fml and undef input is disabled
diff: @@ -204,6 +204,11 @@ static expr preprocess(Transform &t, const set<expr> &qvars,
  for (auto &[e, v] : instances) {
  for (unsigned i = 0; i <= 2; ++i) {
  + if (config::disable_undef_input && i == 1)
  + continue;
  + if (config::disable_poison_input && i == 2)
  + continue;
  +
  expr newexpr = e.subst(var, nums[i]);
  if (newexpr.eq(e)) {
  instances2[move(newexpr)] = v;
  