{"ast_node_type":"function","tokens":[{"end":72,"kind":"keyword","start":0,"text":"fn"}]}
    fn add_to_diag<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
impl Subdiagnostic for NonBindingLetSub {
        let can_suggest_binding = self.drop_fn_start_end.is_some() || !self.is_assign_desugar;