build: add additional sources for CMake build

Add missing sources that are needed for building with CMake.

Fixes: #747

Author: compnerd

Sources/SwiftWin32/CMakeLists.txt

@@ -99,6 +99,10 @@ target_sources(SwiftWin32 PRIVATE
   "View Controllers/PresentationController.swift"
   "View Controllers/ViewController.swift"
   "Views and Controls/Axis.swift"
+  "Views and Controls/BarItem.swift"
+  "Views and Controls/BarButtonItem.swift"
+  "Views and Controls/BarButtonItemGroup.swift"
+  "Views and Controls/BarPositioning.swift"
   "Views and Controls/Button.swift"
   "Views and Controls/Control.swift"
   "Views and Controls/DatePicker.swift"
@@ -107,6 +111,7 @@ target_sources(SwiftWin32 PRIVATE
   "Views and Controls/EdgeInsets.swift"
   "Views and Controls/ImageView.swift"
   "Views and Controls/Label.swift"
+  "Views and Controls/Offset.swift"
   "Views and Controls/PickerView.swift"
   "Views and Controls/ProgressView.swift"
   "Views and Controls/Slider.swift"