Apps don't weak-link our overlays today, so if the overlays strong-link
to frameworks apps won't launch on older OSs. This was causing failures
on the buildbot, but is actually a serious issue for our developers.
Swift SVN r31180
On OS X 10.10 and earlier, CoreImage is a sub-framework of QuartzCore.
Users of CoreImage use "import QuartzCore" and link against QuartzCore.
On OS X 10.11 (and in the OS X 10.11 SDK), CoreImage is a top-level
framework. Users of CoreImage use "import CoreImage" and would link against
CoreImage. Of course, QuartzCore continues to re-export CoreImage's API.
When backwards-deploying, we need to continue linking against QuartzCore,
but still need to bring in the overlay if you import CoreImage. That's
what this patch does.
rdar://problem/20196610
Swift SVN r28449
This change depends on a coordinated SceneKit change which makes the
original method unavailable to avoid ambiguity. The API also requires a
data file, so no tests yet.
rdar://20384835
Swift SVN r27319
