Added SDL_isinf(), SDL_isinff(), SDL_isnan(), and SDL_isnanf()

include/build_config/SDL_build_config_wingdk.h

@@ -111,6 +111,10 @@
 #define HAVE_FABS   1
 #define HAVE_FLOOR  1
 #define HAVE_FMOD   1
+#define HAVE_ISINF  1
+#define HAVE_ISINF_FLOAT_MACRO 1
+#define HAVE_ISNAN  1
+#define HAVE_ISNAN_FLOAT_MACRO 1
 #define HAVE_LOG    1
 #define HAVE_LOG10  1
 #define HAVE_POW    1