syntax_data: {"ast_node_type":"function","tokens":[{"end":87,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
context_before: impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
context_after:         // Make sure we know where in the MIR we are.