syntax_data: {"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Labels for where incompatibility-causing by-ref default binding modes were introduced.
context_before:     default_mode_span: Option<(Span, ty::Mutability)>,
context_after:     // FIXME(ref_pat_eat_one_layer_2024_structural): To track the default binding mode, we duplicate