Function rustdoc::doctest::doctest_run_fn

fn doctest_run_fn(
    test_opts: IndividualTestOptions,
    global_opts: GlobalTestOptions,
    scraped_test: ScrapedDoctest,
    rustdoc_options: Arc<Options>,
    unused_externs: Arc<Mutex<Vec<UnusedExterns>>>,
) -> Result<(), String>