Fixed compiler warning on 32-bit Mac OS X.

src/video/cocoa/SDL_cocoawindow.m

@@ -401,7 +401,7 @@ static __inline__ void ConvertNSRect(NSRect *r)
     enumerator = [touches objectEnumerator];
     touch = (NSTouch*)[enumerator nextObject];
     while (touch) {
-        SDL_TouchID touchId = (SDL_TouchID)[touch device];
+        const SDL_TouchID touchId = (SDL_TouchID) ((size_t) [touch device]);
         if (!SDL_GetTouch(touchId)) {
             SDL_Touch touch;
 
@@ -421,7 +421,7 @@ static __inline__ void ConvertNSRect(NSRect *r)
             }
         } 
 
-        SDL_FingerID fingerId = (SDL_FingerID)[touch identity];
+        const SDL_FingerID fingerId = (SDL_FingerID) ((size_t) [touch identity]);
         float x = [touch normalizedPosition].x;
         float y = [touch normalizedPosition].y;
         /* Make the origin the upper left instead of the lower left */