message: fix submatrix generation for empty and full rows
diff: @@ -1632,12 +1632,14 @@ std::unique_ptr<Dense<ValueType>> Dense<ValueType>::create_submatrix_impl(
  row_major_range range_this{this->get_values(), this->get_size()[0],
  this->get_size()[1], this->get_stride()};
  auto range_result = range_this(rows, columns);
  + size_type storage_size =
  + rows.length() > 0
  + ? range_result.length(0) * this->get_stride() - columns.begin
  + : 0;
  return Dense::create(
  this->get_executor(),
  dim<2>{range_result.length(0), range_result.length(1)},
  - make_array_view(this->get_executor(),
  - range_result.length(0) * this->get_stride(),
  - range_result->data),
  + make_array_view(this->get_executor(), storage_size, range_result->data),
  stride);
  }
  