syntax_data: {"ast_node_type":"variable","tokens":[{"end":41,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let old_dedup_scope =
context_before:                 self.in_scope(arm_scope, arm.lint_level, |this| {
context_after:                         mem::replace(&mut this.fixed_temps_scope, Some(arm.scope));