Do the tzname -> _tzname mapping for ALL Win32 builds:

We need this for MSVC2013 and MSVC2017 builds.

src/xpdev/genwrap.h

@@ -276,9 +276,7 @@ DLLEXPORT int DLLCALL	get_errno(void);
 	#define SLEEP(x)		Sleep(x)
 	#define	popen			_popen
 	#define pclose			_pclose
-	#if !(defined(_MSC_VER) || defined(__MSVCRT__))	/* Conflicts with latest (Windows 2003 R2) PlatformSDK include/time.h */
-		#define tzname			_tzname
-	#endif
+	#define tzname			_tzname
 
 #elif defined(__OS2__)