{"ast_node_type":"variable","tokens":[{"end":49,"kind":"keyword","start":0,"text":"if"}]}
    if let None = fcx.infcx.tainted_by_errors() {
    // Handle potentially region dependent goals, see `InferCtxt::in_hir_typeck`.
        for obligation in fcx.take_hir_typeck_potentially_region_dependent_goals() {