syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"$self.tcx.is_diagnostic_item(rustc_span::sym::$adt,"}]}
source_snippet:                     $self.tcx.is_diagnostic_item(rustc_span::sym::$adt, adt_def.did()) &&
context_before:                 ExprKind::Adt(box AdtExpr { adt_def, variant_index, .. }) if {
context_after:                     adt_def.variants()[*variant_index].name == rustc_span::sym::$variant