[ONNX] Fix shrink operator for uint* types (#3188)

* Fix shrink operator for uint* types

* Add a comment for negative_lambd=0 for uint*

src/ngraph/frontend/onnx_import/op/shrink.cpp

@@ -43,14 +43,26 @@ namespace ngraph
                     ASSERT_VALID_ARGUMENT(node, !(lambd < 0.0f))
                         << " The provided 'lambd' value:" << lambd << " must not be negative.";
 
-                    const auto negative_lambd = ngraph::op::Constant::create(
-                        input->get_element_type(), input->get_shape(), {-lambd});
+                    std::shared_ptr<ngraph::op::Constant> negative_lambd;
+                    const auto input_element_type = input->get_element_type();
+                    if (input_element_type.is_signed())
+                    {
+                        negative_lambd = ngraph::op::Constant::create(
+                            input_element_type, input->get_shape(), {-lambd});
+                    }
+                    else
+                    {
+                        // Passing -lambd to unsigned type constant will cause an overflow.
+                        // For unsigned types the lowest possible value is 0.
+                        negative_lambd = ngraph::op::Constant::create(
+                            input_element_type, input->get_shape(), {0});
+                    }
 
                     const auto positive_lambd = ngraph::op::Constant::create(
-                        input->get_element_type(), input->get_shape(), {lambd});
+                        input_element_type, input->get_shape(), {lambd});
 
                     const auto bias_tensor = ngraph::op::Constant::create(
-                        input->get_element_type(), input->get_shape(), {bias});
+                        input_element_type, input->get_shape(), {bias});
 
                     // Create a mask indicating locations of values that need to be adjusted
                     // by adding and subtracting bias
@@ -63,9 +75,9 @@ namespace ngraph
                     // Convert from bool to the input type to be able to multiply adjusted inputs
                     // by the created masks
                     values_below_neg_lambd = std::make_shared<ngraph::op::Convert>(
-                        values_below_neg_lambd, input->get_element_type());
+                        values_below_neg_lambd, input_element_type);
                     values_above_pos_lambd = std::make_shared<ngraph::op::Convert>(
-                        values_above_pos_lambd, input->get_element_type());
+                        values_above_pos_lambd, input_element_type);
 
                     std::shared_ptr<ngraph::Node> input_minus_bias = input - bias_tensor;
                     std::shared_ptr<ngraph::Node> input_plus_bias = input + bias_tensor;