Add Xbox UWP port

ports/uwp/app/main.cpp

@@ -0,0 +1,31 @@
+#include <Windows.h>
+#include <SDL.h>
+#include <string>
+#include <winrt/Windows.ApplicationModel.h>
+#include <winrt/Windows.Storage.h>
+
+extern "C" int SDL_main(int argc, char **argv);
+
+namespace
+{
+
+int runLove(int, char **)
+{
+    std::wstring packagePath = winrt::Windows::ApplicationModel::Package::Current()
+        .InstalledLocation().Path().c_str();
+    std::string gamePath = winrt::to_string(packagePath + L"\\gen1recomp.love");
+
+    char executable[] = "Gen1RecompUWP";
+    char fused[] = "--fused";
+    char *loveArgv[] = {executable, gamePath.data(), fused, nullptr};
+    return SDL_main(3, loveArgv);
+}
+
+} // namespace
+
+int CALLBACK WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
+{
+    SDL_SetHint(SDL_HINT_WINRT_HANDLE_BACK_BUTTON, "1");
+    OutputDebugStringA("Gen1Recomp UWP startup\n");
+    return SDL_WinRTRunApp(runLove, nullptr);
+}