[CP-SAT] revisit cut code; add new API to MaxBoundedSubsetSum

ortools/sat/integer_expr.cc

@@ -824,7 +824,7 @@ bool ProductPropagator::CanonicalizeCases() {
         p_.GreaterOrEqual(0), {a_.GreaterOrEqual(0), b_.GreaterOrEqual(0)});
   }
 
-  // Otherwise, make sure p is non-negative or accros zero.
+  // Otherwise, make sure p is non-negative or across zero.
   if (integer_trail_->UpperBound(p_) <= 0) {
     if (integer_trail_->LowerBound(a_) < 0) {
       DCHECK_GT(integer_trail_->UpperBound(a_), 0);