Fixed a few public APIs that we accidentally neglected to mark as SDLCALL.

Fixes Bugzilla #2262.

include/SDL_joystick.h

@@ -115,7 +115,7 @@ extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joys
  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
  *  (32 for the string plus a NULL terminator).
  */
-extern DECLSPEC void SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
+extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
 
 /**
  *  convert a string into a joystick formatted guid

include/SDL_main.h

@@ -101,7 +101,7 @@ extern "C" {
  *  Calling this yourself without knowing what you're doing can cause
  *  crashes and hard to diagnose problems with your application.
  */
-extern DECLSPEC void SDL_SetMainReady(void);
+extern DECLSPEC void SDLCALL SDL_SetMainReady(void);
 
 #ifdef __WIN32__
 

include/SDL_render.h

@@ -596,7 +596,7 @@ extern DECLSPEC void SDLCALL SDL_RenderGetScale(SDL_Renderer * renderer,
  *
  *  \return 0 on success, or -1 on error
  */
-extern DECLSPEC int SDL_SetRenderDrawColor(SDL_Renderer * renderer,
+extern DECLSPEC int SDLCALL SDL_SetRenderDrawColor(SDL_Renderer * renderer,
                                            Uint8 r, Uint8 g, Uint8 b,
                                            Uint8 a);
 
@@ -612,7 +612,7 @@ extern DECLSPEC int SDL_SetRenderDrawColor(SDL_Renderer * renderer,
  *
  *  \return 0 on success, or -1 on error
  */
-extern DECLSPEC int SDL_GetRenderDrawColor(SDL_Renderer * renderer,
+extern DECLSPEC int SDLCALL SDL_GetRenderDrawColor(SDL_Renderer * renderer,
                                            Uint8 * r, Uint8 * g, Uint8 * b,
                                            Uint8 * a);