syntax_data: {"ast_node_type":"function","tokens":[{"end":84,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn miri_unleashed_feature(&self, span: Span, feature_gate: Option<Symbol>) {
context_before: impl Session {
context_after:         self.miri_unleashed_features.lock().push((span, feature_gate));