"incompatible target" when trying Gold linker for arm-none-eabi

[Cary Coutant]

> I think Gold should always accept options -plugin , --plugin , or whatever
> it can take. If it has not been built with plug-in support, then it should
> print an error message that says exactly that. This way, other users will
> not waste their precious time too anymore. 8-)

Good idea. I'll go ahead and fix that.

While I'm at it, it's probably also a good idea to turn on plugin
support by default.

-cary