While the swift compiler in Xcode links against tbd files in the sdk
that contain an armv7k slice, the open source swift toolchain links
against the stdlib dylb that is in the toolchain itself. This means that
we cannot drop support for armv7k support in the stdlib dylib without
losing support for building armv7k when back deploying to older watch
targets. For now, roll back the recent deployment target bump from 9.0
to 6.0 so that we keep armv7k and i386 simulator.
rdar://135560598
Bump the deployment target from macOS 10.13-aligned versions to macOS
13.0-aligned versions. This allows us to stop linking CoreFoundation
in the swift runtime, which was previously required for availability
checking. It also lets us align the deployment target on x86_64 with
arm64, which was 11.0. Finally, it is a prerequisite to being able to
build swift using the macOS 15 beta SDKs.
For every struct type for which the frameworks provides an NSValue category for boxing and unboxing values of that type, provide an _ObjectiveCBridgeable conformance in the Swift overlay that bridges that struct to NSValue, allowing the structs to be used naturally with id-as-Any APIs and Cocoa container classes. This is mostly a matter of gyb-ing out boilerplate using `NSValue.init(bytes:objCType:)` to construct the instance, `NSValue.objCType` to check its type when casting, and `NSValue.getValue(_:)` to extract the unboxed value, though there are a number of special snowflake cases that need special accommodation:
- To maintain proper layering, CoreGraphics structs need to be bridged in the Foundation overlay.
- AVFoundation provides the NSValue boxing categories for structs owned by CoreMedia, but it does so using its own internal subclasses of NSValue, and these subclasses do not interop properly with the standard `NSValue` subclasses instantiated by Foundation. To do the right thing, we therefore have to let AVFoundation provide the bridging implementation for the CoreMedia types, and we have to use its category methods to do so.
- SceneKit provides NSValue categories to box and unbox SCNVector3, SCNVector4, and SCNMatrix4; however, the methods it provides do so in an unusual way. SCNVector3 and SCNVector4 are packaged into `CGRect`s and then the CGRect is boxed using `valueWithCGRect:`. SCNMatrix4 is copied into a CATransform3D, which is then boxed using `valueWithCATransform3D:` from CoreAnimation. To be consistent with what SceneKit does, use its category methods for these types as well, and when casting, check the type against the type encoding SceneKit uses rather than the type encoding of the expected type.
