Fixed compiling on Windows with HAVE_LIBC enabled
diff --git a/include/SDL_config_windows.h b/include/SDL_config_windows.h
index ca8e0c1..61881ee 100644
--- a/include/SDL_config_windows.h
+++ b/include/SDL_config_windows.h
@@ -109,13 +109,15 @@ typedef unsigned int uintptr_t;
#define HAVE_MEMCMP 1
#define HAVE_STRLEN 1
#define HAVE__STRREV 1
-#define HAVE__STRUPR 1
-#define HAVE__STRLWR 1
+/* These functions have security warnings, so we won't use them */
+/* #undef HAVE__STRUPR */
+/* #undef HAVE__STRLWR */
#define HAVE_STRCHR 1
#define HAVE_STRRCHR 1
#define HAVE_STRSTR 1
-#define HAVE__LTOA 1
-#define HAVE__ULTOA 1
+/* These functions have security warnings, so we won't use them */
+/* #undef HAVE__LTOA */
+/* #undef HAVE__ULTOA */
#define HAVE_STRTOL 1
#define HAVE_STRTOUL 1
#define HAVE_STRTOD 1