isinf and isnan declarations win32/apple

include/lmms_math.h

@@ -28,10 +28,20 @@
 
 #include <stdint.h>
 #include "lmms_constants.h"
+#include "lmmsconfig.h"
 #include <QtCore/QtGlobal>
 
 #include <math.h>
 
+#if defined (LMMS_BUILD_WIN32) || defined (LMMS_BUILD_APPLE) 
+#ifndef isnanf
+#define isnanf(x)	isnan(x)
+#endif
+#ifndef isinff
+#define isinff(x)	isinf(x)
+#endif
+#endif
+
 #ifdef __INTEL_COMPILER
 
 static inline float absFraction( const float _x )