Check for socklen_t type using C++ mode (since gsocket.cpp is now C++ code).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@28846 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

configure.in

@@ -4951,6 +4951,10 @@ if test "$wxUSE_SOCKETS" = "yes" ; then
     dnl like mingw does..  -- RL
     if test "$TOOLKIT" != "MSW"; then
         dnl determine the type of third argument for getsockname
+	dnl This test needs to be done in C++ mode since gsocket.cpp now
+	dnl is C++ code and pointer cast that are possible even without
+	dnl warning in C still fail in C++.
+	AC_LANG_PUSH(C++)
         AC_CACHE_CHECK([what is the type of the third argument of getsockname],
                        wx_cv_type_getsockname3,
             [
@@ -5011,6 +5015,7 @@ if test "$wxUSE_SOCKETS" = "yes" ; then
         else
             AC_DEFINE_UNQUOTED(SOCKLEN_T, $wx_cv_type_getsockname3)
         fi
+	AC_LANG_POP
     fi
 fi