Fix Xcode project generation build tests to pass the platform to `xcodebuild` (#3347)
Fix Xcode project generation build tests to pass the platform to `xcodebuild` (#3347)

Pass `-destination` `platform=macOS` to `xcodebuild` to be specific about the destination.  This is more robust.
apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager