With new gcc9 how to handle error from -Werror=address-of-packed-member

[Florian Weimer]

* Normand:

> With new gcc9 there are new error reported by
> -Werror=address-of-packed-member
> How to handle such error ?
>
> eg:
> libflash/ecc.c:419:24: error: taking address of packed member of
> 'struct ecc64' may result in an unaligned pointer value
> [-Werror=address-of-packed-member]
>   419 |   memcpy(inc_uint64_by(&ecc_word.data, alignment), src,
> bytes_wanted);
>       |                        ^~~~~~~~~~~~~~

What does the definition of struct ecc64 look like?

Thanks,
Florian