Change Default Linker to Gold for x86

[Kaiede]

For the same reasons that most platforms rely on the gold linker to be the default, x86/i686 needs it to be the default to avoid issues when using swift/swiftc to build/link modules.

[compnerd]

This is totally reasonable. I am left wondering how much it makes sense to have this though. Why not just give up on BFD and default to gold always unless the user requests lld?

[compnerd]

I think that it might make sense to have a test for the default linker.

[compnerd]

@swift-ci please test

[Kaiede]

This is totally reasonable. I am left wondering how much it makes sense to have this though. Why not just give up on BFD and default to gold always unless the user requests lld?

That's a fair question. Seems like perhaps it should be the way to go, especially in the face of work around ABI stabilization that really seems to be dependent on things that BFD doesn't currently support or handle well.

[compnerd]

I think that we could/should do that as a follow up. Although, I think that it is reasonable to add a driver test to ensure that gold is used by default.

[futurejones]

This is totally reasonable. I am left wondering how much it makes sense to have this though. Why not just give up on BFD and default to gold always unless the user requests lld?

But at this point in time it is not the case, so we need to approve this PR and others like it without any delays.

[gottesmm]

I agree with compnerd here. As a follow up commit we should add a test to make sure that we do not use BFD here.

[compnerd]

@gottesmm - I'll go ahead and merge to get people unblocked. I was holding off hoping that they would have a test case with the change itself.

[futurejones]

@compnerd Thanks!