syntax_data: {"ast_node_type":"variable","tokens":[{"end":74,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                 if let Some(coverage_info) = this.coverage_info.as_mut() {
context_before:                 // (Skipped if branch coverage is not enabled.)
context_after:                     coverage_info.visit_unary_not(this.thir, expr_id);