Fixed VS compilation (no isnan, isinf on VS).

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@6693 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/bullet/src/BulletCollision/CollisionDispatch/btCollisionObject.h

@@ -16,6 +16,13 @@ subject to the following restrictions:
 #ifndef COLLISION_OBJECT_H
 #define COLLISION_OBJECT_H
 
+#if defined(WIN32) && !defined(__CYGWIN__)
+#  define isnan _isnan
+#  define isinf(x) (!_finite(x))
+#else
+#  include <math.h>
+#endif
+
 #include "LinearMath/btTransform.h"
 
 //island management, m_activationState1