Limit SDL2 SysWM header to Windows users

src/event.c

@@ -43,6 +43,12 @@
 #include "hacks.h"
 #include "volume.h"
 
+#if defined(_WIN32) && XSYSTEM35_SDL_VERSION == 2
+#include <SDL_syswm.h>
+// Windows defines this name too; the key table below uses input.h's enum.
+#undef KEY_EXECUTE
+#endif
+
 static void get_event(void);
 static void keyEventProsess(SDL_KeyboardEvent *e, bool pressed);
 

src/sdl_compat.h

@@ -11,9 +11,6 @@
 
 #if XSYSTEM35_SDL_VERSION == 2
 #include <SDL.h>
-#ifdef _WIN32
-#include <SDL_syswm.h>
-#endif
 #elif XSYSTEM35_SDL_VERSION == 3
 #include <SDL3/SDL.h>
 #else

src/win/window.h

@@ -4,6 +4,10 @@
 #include <windows.h>
 #include "sdl_compat.h"
 
+#if XSYSTEM35_SDL_VERSION == 2
+#include <SDL_syswm.h>
+#endif
+
 static inline HWND win_get_hwnd(SDL_Window *window)
 {
 #if XSYSTEM35_SDL_VERSION == 2