The convertible_to traits need to use a variadic catch-all for the false-cases.

The convertible_to traits need to use a variadic catch-all for the
false-cases.
* include/std/istream (__is_convertible_to_basic_istream):
Change the parameter of the false-case of __check to a variadic.
* include/std/ostream (__is_convertible_to_basic_ostream):
Likewise.

From-SVN: r243098

libstdc++-v3/ChangeLog

+2016-12-01  Ville Voutilainen  <ville.voutilainen@gmail.com>
+
+	The convertible_to traits need to use a variadic catch-all for the
+	false-cases.
+	* include/std/istream (__is_convertible_to_basic_istream):
+	Change the parameter of the false-case of __check to a variadic.
+	* include/std/ostream (__is_convertible_to_basic_ostream):
+	Likewise.
+
 2016-12-01  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* crossconfig.m4 (*-linux*): Add link-check for memalign.

libstdc++-v3/include/std/istream

@@ -915,7 +915,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       template<typename _Ch, typename _Up>
       static basic_istream<_Ch, _Up>& __check(basic_istream<_Ch, _Up>*);
 
-      static void __check(void*);
+      static void __check(...);
     public:
       using istream_type =
 	decltype(__check(declval<typename remove_reference<_Tp>::type*>()));

libstdc++-v3/include/std/ostream

@@ -619,7 +619,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     template<typename _Ch, typename _Up>
     static basic_ostream<_Ch, _Up>& __check(basic_ostream<_Ch, _Up>*);
 
-    static void __check(void*);
+    static void __check(...);
   public:
     using ostream_type =
       decltype(__check(declval<typename remove_reference<_Tp>::type*>()));