syntax_data: {"ast_node_type":"variable","tokens":[{"end":53,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                                 let span = expr.span;
context_before:                             let (Some(value), Some(_)) = (value, dest.label) else {
context_after:                                 self.tcx.dcx().emit_fatal(ConstContinueMissingLabelOrValue { span })