message: Issue DeValue Window Calculations
  Cast default value expressions at bind time so that
  PhysicalWindowOperator can just copy.
diff: @@ -67,6 +67,7 @@ BindResult SelectBinder::BindWindow(WindowExpression &window, idx_t depth) {
  BindChild(window.end_expr, depth, error);
  BindChild(window.offset_expr, depth, error);
  BindChild(window.default_expr, depth, error);
  +
  this->inside_window = false;
  if (!error.empty()) {
  // failed to bind children of window function
  @@ -125,6 +126,12 @@ BindResult SelectBinder::BindWindow(WindowExpression &window, idx_t depth) {
  auto expression = GetExpression(order.expression);
  result->orders.emplace_back(type, null_order, move(expression));
  }
  +
  + if (window.default_expr) {
  + auto &default_expr = (BoundExpression &)*window.default_expr;
  + default_expr.expr = BoundCastExpression::AddCastToType(move(default_expr.expr), result->return_type);
  + }
  +
  result->start_expr = GetExpression(window.start_expr);
  result->end_expr = GetExpression(window.end_expr);
  result->offset_expr = GetExpression(window.offset_expr);
  