Make sure some win32 defines exist.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3581 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CIrrDeviceWin32.h

@@ -18,6 +18,10 @@
 	#include <mmsystem.h> // For JOYCAPS
 	#include <Windowsx.h>
 #endif
+#if !defined(GET_X_LPARAM)
+#define GET_X_LPARAM(lp) ((int)(short)LOWORD(lp))
+#define GET_Y_LPARAM(lp) ((int)(short)HIWORD(lp))
+#endif
 
 namespace irr
 {