message: #[serde(transparent)] for SyntaxContext
diff: @@ -23,6 +23,7 @@ use std::fmt;
  /// A SyntaxContext represents a chain of macro expansions (represented by
  /// marks).
  #[derive(Clone, Copy, PartialEq, Eq, Default, PartialOrd, Ord, Hash, Serialize, Deserialize)]
  +#[serde(transparent)]
  pub struct SyntaxContext(u32);
  #[derive(Copy, Clone, Debug)]
  