cmdutils: Use a configure check for enabling CommandLineToArgvW

This simplifies the condition to avoid hardcoding the systems
where the function exists. This also simplifies support for
newer Windows API subsets where this function doesn't exist,
such as Windows Phone 8 and the "metro" API subset of Windows 8.
Signed-off-by: Martin Storsjö <martin@martin.st>

cmdutils.c

@@ -166,7 +166,7 @@ static const OptionDef *find_option(const OptionDef *po, const char *name)
     return po;
 }
 
-#if defined(_WIN32) && !defined(__MINGW32CE__)
+#if HAVE_COMMANDLINETOARGVW
 #include <windows.h>
 #include <shellapi.h>
 /* Will be leaked on exit */
@@ -226,7 +226,7 @@ static inline void prepare_app_arguments(int *argc_ptr, char ***argv_ptr)
 {
     /* nothing to do */
 }
-#endif /* WIN32 && !__MINGW32CE__ */
+#endif /* HAVE_COMMANDLINETOARGVW */
 
 int parse_option(void *optctx, const char *opt, const char *arg,
                  const OptionDef *options)

configure

@@ -1181,6 +1181,7 @@ HAVE_LIST="
     attribute_packed
     closesocket
     cmov
+    CommandLineToArgvW
     cpunop
     CryptGenRandom
     dcbzl