message: add #[doc(hidden)] to __SalsaQueryDescriptor
diff: @@ -523,13 +523,9 @@ macro_rules! database_storage {
  )*
  }
  - /// Identifies a query and its key. You are not meant to name
  - /// this type directly or use its fields etc. It is a
  - /// **private query descriptor type generated by salsa** and
  - /// its exact structure is subject to change. Sadly, I don't
  - /// know any way to hide this with hygiene, so use `__`
  - /// instead.
  + /// Identifies a query and its key.
  #[derive(Clone, Debug, PartialEq, Eq, Hash)]
  + #[doc(hidden)]
  $v struct __SalsaQueryDescriptor {
  kind: __SalsaQueryDescriptorKind
  }
  