Don't fail in constant folding if we try to materialize a DT_VARIANT …

…or DT_RESOURCE.

Addresses: #29525

PiperOrigin-RevId: 257703800

tensorflow/core/grappler/optimizers/constant_folding.cc

@@ -1090,7 +1090,9 @@ Status CreateConstantTensorAttrValue(DataType type, double value,
       SET_TENSOR_VAL_CASE(DT_QUINT8, int32, int);
       SET_TENSOR_VAL_CASE(DT_BOOL, bool, bool);
     default:
-      return errors::InvalidArgument("Unsupported type: ", type);
+      return errors::InvalidArgument(
+          "Unsupported type in CreateConstantTensorAttrValue: ",
+          DataTypeString(type));
   }
   return Status::OK();
 }
@@ -1888,13 +1890,15 @@ Status ConstantFolding::ReplaceOperationWithConstant(
     double value, const GraphProperties& properties,
     const TensorShapeProto& shape, NodeDef* node, GraphDef* graph) {
   const DataType dtype = GetDataTypeFromNodeOrProps(*node, properties);
-  if (dtype == DT_INVALID) {
+  AttrValue tensor_attr;
+  Status s = CreateConstantTensorAttrValue(dtype, value, shape, &tensor_attr);
+  if (!s.ok()) {
+    // Fail gracefully without mutating the graph.
+    VLOG(1) << "Failed to replace node " << node->name() << " of type "
+            << DataTypeString(dtype) << " with constant tensor of value "
+            << value;
     return Status::OK();
   }
-
-  AttrValue tensor_attr;
-  TF_RETURN_IF_ERROR(
-      CreateConstantTensorAttrValue(dtype, value, shape, &tensor_attr));
   return ReplaceOperationWithConstantTensor(dtype, tensor_attr.mutable_tensor(),
                                             node, graph);
 }