Allow compiling with Clang
https://bugs.gentoo.org/739330

--- a/src/sdlhandler.cpp
+++ b/src/sdlhandler.cpp
@@ -1034,10 +1034,10 @@
 bool SDLHandler::intersects( int x, int y, int w, int h,
                              int x2, int y2, int w2, int h2 ) {
 	SDL_Rect ra = {
-		x, y, w, h
+		static_cast<Sint16>(x), static_cast<Sint16>(y), static_cast<Uint16>(w), static_cast<Uint16>(h)
 	};
 	SDL_Rect rb = {
-		x2, y2, w2, h2
+		static_cast<Sint16>(x2), static_cast<Sint16>(y2), static_cast<Uint16>(w2), static_cast<Uint16>(h2)
 	};
 	return intersects( &ra, &rb );
 }