[patch] Transfer ownership of the gold plugin

[Rafael Espíndola via llvm-commits]

>> As part of that I asked Teresa if she could take over ownership of
>> tools/gold. With all the work on thinlto she is one of the most active
>> developers in the area and I am sure will do an excellent job at it.
>
> That works for me, so long as Teresa is on board with it.  Please keep the CODE_OWNERS list properly sorted though.

Yes, I contacted her off list first.

Fixed the order and committed as r274574.

Cheers,
Rafael