Fix issue 2258 where dependency target binaries are not copied

[rikkimax]

This is very likely to create issues surrounding shared library support in ldc (it will detect regressions), I have entirely left out dmd and gdc support right now.

Fixes #2258.

[rikkimax]

Okay, looks like I have broken CI somewhat for *nix.

I won't fix that tonight.

But it is working locally for my code base. So close!

[rikkimax]

After thinking about this, I think I am doing this the wrong way.

For instance the build directory may not even exist by the time I do the copy.

I'll have to start again.

[rikkimax]

TIL: determining build artifacts in dub is pretty complicated.

But last build had a couple of green *nix platforms with test running for ldc, so looks like this should be green now.

[rikkimax]

I think I got super unlucky and just missed a fix for vibe.d that landed only a few minutes after the CI tests went and got built.

vibe-d/vibe.d#2668

As a result this should probably be green now.

[rikkimax]

Okay this isn't just me: vibe-d/vibe.d#2647

So it's actually green yay.

[WebFreak001]

change LGTM

I don't really have much experience with shared libraries on windows platforms, can you link to some reference why .lib and .exp also need to be copied to the target path? I thought they would be compiled in statically and not need to be copied.

[rikkimax]

I don't really have much experience with shared libraries on windows platforms, can you link to some reference why .lib and .exp also need to be copied to the target path? I thought they would be compiled in statically and not need to be copied.

They are compiled in statically yes.

You may want to distribute them for shared libraries, even if they are also being used as a dependency. In that combination, there is no reason to not copy them. It's common enough.

The copying of executable import and export libraries I am not sure is correct, but I am erring on the side of caution and doing it regardless because the last thing we want is people having to dig into .dub for these files.

"change LGTM"