[PATCH v2] Set the sh_entsize field of .stab to 12

[Fangrui Song]

On 2020-04-09, Nick Clifton wrote:
>Hi Fangrui,
>
>>>     PR gas/25768
>>>     * elf.c (assign_section_numbers): Set .stab sh_entsize to 12.
>
>Approved - please apply.
>
>> Ping :)
>
>Sorry - I blame the weather - or aliens - or anything but my own laziness.
>
>Cheers
>  Nick

No worries! Nick, can you apply it on my behalf? I don't have a commit bit.