Adding void to empty function prototype parenthesis

src/core/unix/SDL_appid.h

@@ -24,7 +24,7 @@ freely, subject to the following restrictions:
 #ifndef SDL_appid_h_
 #define SDL_appid_h_
 
-extern const char *SDL_GetExeName();
-extern const char *SDL_GetAppID();
+extern const char *SDL_GetExeName(void);
+extern const char *SDL_GetAppID(void);
 
 #endif // SDL_appid_h_

src/events/SDL_mouse.c

@@ -1254,7 +1254,7 @@ void SDL_PerformWarpMouseInWindow(SDL_Window *window, float x, float y, bool ign
     }
 }
 
-void SDL_DisableMouseWarpEmulation()
+void SDL_DisableMouseWarpEmulation(void)
 {
     SDL_Mouse *mouse = SDL_GetMouse();
 

src/video/x11/SDL_x11sym.h

@@ -158,7 +158,7 @@ SDL_X11_SYM(Status,XmbTextListToTextProperty,(Display* a,char** b,int c,XICCEnco
 SDL_X11_SYM(Region,XCreateRegion,(void),(),return)
 SDL_X11_SYM(int,XUnionRectWithRegion,(XRectangle *a, Region b, Region c),(a,b,c), return)
 SDL_X11_SYM(void,XDestroyRegion,(Region),(a),)
-SDL_X11_SYM(void,XrmInitialize,(),(),)
+SDL_X11_SYM(void,XrmInitialize,(void),(),)
 SDL_X11_SYM(char*,XResourceManagerString,(Display *display),(display),)
 SDL_X11_SYM(XrmDatabase,XrmGetStringDatabase,(char *data),(data),)
 SDL_X11_SYM(void,XrmDestroyDatabase,(XrmDatabase db),(db),)