syntax_data: {"ast_node_type":"variable","tokens":[{"end":85,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let source_info = self.source_info(subcandidate.extra_data.span);
context_before:                     // That block is already unreachable but needs a terminator to make the MIR well-formed.
context_after:                     self.cfg.terminate(block, source_info, TerminatorKind::Unreachable);