Add visionOS slices to the XCFramework

Archive Compute for visionOS and the visionOS Simulator and include both
in Compute.xcframework.

Use canImport(Darwin) for the attribute vtable and type description
branches in Swift. The C headers select these declarations with
TARGET_OS_MAC, so visionOS must use the Darwin branch as well.

Author: Kyle-Ye

Scripts/create-xcframework.sh

@@ -25,12 +25,28 @@ xcodebuild archive \
     -archivePath "$BUILD_DIR/Archives/Compute-iOS-Simulator.xcarchive" \
     ENABLE_USER_SCRIPT_SANDBOXING=NO
 
+xcodebuild archive \
+    -project Xcode/Compute.xcodeproj \
+    -scheme Compute \
+    -destination "generic/platform=visionOS" \
+    -archivePath "$BUILD_DIR/Archives/Compute-visionOS.xcarchive" \
+    ENABLE_USER_SCRIPT_SANDBOXING=NO
+
+xcodebuild archive \
+    -project Xcode/Compute.xcodeproj \
+    -scheme Compute \
+    -destination "generic/platform=visionOS Simulator" \
+    -archivePath "$BUILD_DIR/Archives/Compute-visionOS-Simulator.xcarchive" \
+    ENABLE_USER_SCRIPT_SANDBOXING=NO
+
 rm -rf "$BUILD_DIR/Frameworks/Compute.xcframework"
 
 xcodebuild -create-xcframework \
     -archive "$BUILD_DIR/Archives/Compute-macOS.xcarchive" -framework Compute.framework \
     -archive "$BUILD_DIR/Archives/Compute-iOS.xcarchive" -framework Compute.framework \
     -archive "$BUILD_DIR/Archives/Compute-iOS-Simulator.xcarchive" -framework Compute.framework \
+    -archive "$BUILD_DIR/Archives/Compute-visionOS.xcarchive" -framework Compute.framework \
+    -archive "$BUILD_DIR/Archives/Compute-visionOS-Simulator.xcarchive" -framework Compute.framework \
     -output "$BUILD_DIR/Frameworks/Compute.xcframework"
 
 # Post-process swiftinterface files to replace ComputeCxx references with Compute

Sources/Compute/Attribute/AttributeType.swift

@@ -32,7 +32,7 @@ extension _AttributeType {
         vtable.pointee.self_destroy = { attributeType, body in
             attributeType.pointee.attributeBody._destroySelf(body)
         }
-        #if os(iOS) || os(macOS)
+        #if canImport(Darwin)
         vtable.pointee.self_description = { attributeType, body in
             let description: String
             if let selfType = attributeType.pointee.self_id.type

Sources/Compute/Runtime/Metadata.swift

@@ -45,7 +45,7 @@ extension Metadata {
 extension Metadata: @retroactive CustomStringConvertible {
 
     public var description: String {
-        #if os(iOS) || os(macOS)
+        #if canImport(Darwin)
         return __IAGTypeDescription(self) as String
         #else
         return String(__IAGTypeCopyDescription(self))