syntax_data: {"ast_node_type":"variable","tokens":[{"end":57,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let source_info = self.source_info(span);
context_before:                 // Link up the `otherwise` block of the subtree to `remainder_start`.
context_after:                 self.cfg.goto(branch_otherwise, source_info, remainder_start);