Function execute_fat_lto_work_item

fn execute_fat_lto_work_item<B: ExtraBackendMethods>(
    cgcx: &CodegenContext<B>,
    exported_symbols_for_lto: &[String],
    each_linked_rlib_for_lto: &[PathBuf],
    needs_fat_lto: Vec<FatLtoInput<B>>,
    import_only_modules: Vec<(SerializedModule<B::ModuleBuffer>, WorkProduct)>,
    autodiff: Vec<AutoDiffItem>,
    module_config: &ModuleConfig,
) -> Result<WorkItemResult<B>, FatalError>