Fix ssize_t redefinition errors on WIN64 reported by Alexey Simak

ares/config-win32.h

@@ -196,12 +196,16 @@
 #define RETSIGTYPE void
 
 /* Define ssize_t if it is not an available 'typedefed' type */
-#if (defined(__WATCOMC__) && (__WATCOMC__ >= 1240)) || defined(__POCC__)
+#ifndef _SSIZE_T_DEFINED
+#if (defined(__WATCOMC__) && (__WATCOMC__ >= 1240)) || defined(__POCC__) || \
+    defined(__MINGW32__)
 #elif defined(_WIN64)
 #define ssize_t __int64
 #else
 #define ssize_t int
 #endif
+#define _SSIZE_T_DEFINED
+#endif
 
 /* ---------------------------------------------------------------- */
 /*                          STRUCT RELATED                          */

ares/setup.h

@@ -133,12 +133,6 @@
 
 #ifndef HAVE_CONFIG_H
 
-#if defined(__DJGPP__) || (defined(__WATCOMC__) && (__WATCOMC__ >= 1240)) || \
-    defined(__POCC__)
-#else
-#define ssize_t int
-#endif
-
 #if !defined(HAVE_SYS_TIME_H) && !defined(_MSC_VER) && !defined(__WATCOMC__)
 #define HAVE_SYS_TIME_H
 #endif