Function wasmtime_instance_export_nth 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn wasmtime_instance_export_nth(
    store: WasmtimeStoreContextMut<'_>,
    instance: &Instance,
    index: usize,
    name_ptr: &mut *const u8,
    name_len: &mut usize,
    item: &mut MaybeUninit<wasmtime_extern_t>,
) -> bool