Fixed bug 4159 - Windows headers are included after packing alignment change

lectem

The SDL_syswm.h header includes the windows.h header after including begin_code.h which changes the structure packing alignment.

It seems this is not safe as suggested by the following warning :
warning C4121: 'JOBOBJECT_IO_RATE_CONTROL_INFORMATION_NATIVE_V2': alignment of a member was sensitive to packing

include/SDL_syswm.h

@@ -33,12 +33,6 @@
 #include "SDL_video.h"
 #include "SDL_version.h"
 
-#include "begin_code.h"
-/* Set up for C function definitions, even when using C++ */
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /**
  *  \file SDL_syswm.h
  *
@@ -110,6 +104,12 @@ typedef void *EGLSurface;
 #include "SDL_egl.h"
 #endif
 
+#include "begin_code.h"
+/* Set up for C function definitions, even when using C++ */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  *  These are the various supported windowing subsystems
  */