message: Implement BorrowToSql for an additional type.
  Closes
diff: @@ -1042,6 +1042,19 @@ impl BorrowToSql for &dyn ToSql {
  }
  }
  +impl sealed::Sealed for &(dyn ToSql + Sync) {}
  +
  +/// In async contexts it is sometimes necessary to have the additional
  +/// Sync requirement on parameters for queries since this enables the
  +/// resulting Futures to be Send, hence usable in, e.g., tokio::spawn.
  +/// This instance is provided for those cases.
  +impl BorrowToSql for &(dyn ToSql + Sync) {
  + #[inline]
  + fn borrow_to_sql(&self) -> &dyn ToSql {
  + *self
  + }
  +}
  +
  impl<T> sealed::Sealed for T where T: ToSql {}
  impl<T> BorrowToSql for T
  