Fixed bug 5170 - Build fails when using Visual Studio 2017 with Windows 10 SDK 10.0.19041.0 in uwp

JackBoosY

In src/video/winrt/SDL_winrtgamebar.cpp line 55:

    virtual HRESULT STDMETHODCALLTYPE add_VisibilityChanged(
        __FIEventHandler_1_IInspectable *handler,
        Windows::Foundation::EventRegistrationToken *token) = 0;

The macro __FIEventHandler_1_IInspectable defined in windows.fondation.h(Windows10 SDK 10.0.17763.0) line 3576:
#define __FIVector_1_Windows__CFoundation__CPoint ABI::Windows::Foundation::Collections::__FIVector_1_Windows__CFoundation__CPoint_t

but no longer exists in Windows 10 SDK 10.0.19041.0.
After searching this macro in the sdk include path, I found that it was defined in many header files. But it should be replaced in windows.system.h .

src/video/winrt/SDL_winrtgamebar.cpp

@@ -25,7 +25,7 @@
 /* Windows includes */
 #include <roapi.h>
 #include <windows.foundation.h>
-#include <EventToken.h>
+#include <windows.system.h>
 
 
 /* SDL includes */