[gcc r14-2274] libstdc++: Fix <iosfwd> synopsis test

[gcc r14-2274] libstdc++: Fix <iosfwd> synopsis test

[Jonathan Wakely]

https://gcc.gnu.org/g:f9f05e483984bf89fec7778aaa55ece8ba2a86bb

commit r14-2274-gf9f05e483984bf89fec7778aaa55ece8ba2a86bb
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Jul 3 19:33:18 2023 +0100

    libstdc++: Fix <iosfwd> synopsis test
    
    The <syncstream> header is only supported for the cxx11 ABI. The
    declarations of basic_syncbuf, basic_osyncstream, syncbuf and
    osyncstream were already correctly guarded by a check for
    _GLIBCXX_USE_CXX11_ABI, but the wsyncbuf and wosyncstream declarations
    were not.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/27_io/headers/iosfwd/synopsis.cc: Make wsyncbuf and
            wosyncstream depend on _GLIBCXX_USE_CXX11_ABI.

Diff:
---
 libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc b/libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc
index b6d3fa7a719..12f47ae8133 100644
--- a/libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc
+++ b/libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc
@@ -115,7 +115,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
   typedef basic_ofstream<wchar_t> wofstream;
   typedef basic_fstream<wchar_t>  wfstream;
 
-#if __cplusplus >= 202002L
+#if __cplusplus >= 202002L && _GLIBCXX_USE_CXX11_ABI
   typedef basic_syncbuf<wchar_t>     wsyncbuf;
   typedef basic_osyncstream<wchar_t> wosyncstream;
 #endif