Avoid crash in .mdl loader on 64bit unix systems.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3824 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CAnimatedMeshHalfLife.h

@@ -146,7 +146,9 @@ namespace scene
 	} PACK_STRUCT;
 
 #ifndef ZONE_H
-	typedef void *cache_user_t;
+	// NOTE: this was a void*, but that crashes on 64bit. 
+	// I have found no mdl format desc, so not sure what it's meant to be, but s32 at least works. 
+	typedef s32 cache_user_t;	
 #endif
 
 	// demand loaded sequence groups