swift

419214da - [Runtime] Disable prespecialized metadata if we have overridden images.

[Runtime] Disable prespecialized metadata if we have overridden images. We need to check for overridden images on every image load, otherwise XCTest (among others) may `dlopen()` an image that pulls in something that is overridden, at which point the prespecialized metadata won't match the image we loaded. rdar://125727356