syntax_data: {"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let end_block = this.cfg.start_new_block();
context_before:                     this.cfg.terminate(block, source_info, TerminatorKind::Unreachable);
context_after:                     end_block.unit()