syntax_data: {"ast_node_type":"impl","tokens":[{"end":64,"kind":"keyword","start":0,"text":"adt_has_dtor:"}]}
source_snippet:     adt_has_dtor: impl Fn(ty::AdtDef<'tcx>) -> Option<DtorType>,
context_before:     typing_env: ty::TypingEnv<'tcx>,
context_after:     only_significant: bool,