WIN32 build fix

include/fpmath.h

@@ -59,7 +59,7 @@
 #include <machine/endian.h>
 #endif
 
-#ifdef WIN32
+#ifdef __WIN32__
 #define _LITTLE_ENDIAN 1234
 #define _BIG_ENDIAN    4321
 #define _PDP_ENDIAN    3412