[PATCH] configure: Allow LD to be a linker other than GNU ld and gold

[Fangrui Song]

On 2020-04-08, Florian Weimer wrote:
>* Fangrui Song via Libc-alpha:
>
>> When using lld as the linker, configure prints a confusing message.
>>
>> *** These critical programs are missing or too old: GNU ld
>>
>> lld>=8 can build glibc with very few patches. lld may be built with a
>> custom version information (e.g. git commit ID), so a version check is not
>> useful at all.
>
>If additional patches are still required, we should not change the
>configure check at this time.
>
>To be clear, this is an objection from me.  Sorry.
>
>Thanks,
>Florian

Hi Florian,

Can you help with https://sourceware.org/pipermail/libc-alpha/2020-March/111910.html ?

To be honest, this LD capability check looks very strange to me. I
believe a good configure time check should check the problem explicitly,
rather than the version, e.g. if a known version can silently cause a
bug, then we should reject it. The current version check can just give
false positives and/or false negatives.  https://ewontfix.com/13/

I am doing my best to make the least intrusive change to configure.