[committed] libstdc++: Fixed iosfwd/synopsis.cc test for _GLIBCXX_USE_CXX11_ABI=0.

[Tomasz Kamiński]

__cpp_lib_syncbuf (and the corresponding feature) is only available for
CXX11 string API.

libstdc++-v3/ChangeLog:

	* testsuite/27_io/headers/iosfwd/synopsis.cc: Test __cpp_lib_syncbuf
	value only if _GLIBCXX_USE_CXX11_ABI.
---
Pushed to trunk. Tested on x86_64-linux.

 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 81b158b8128..ddbb6411619 100644
--- a/libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc
+++ b/libstdc++-v3/testsuite/27_io/headers/iosfwd/synopsis.cc
@@ -11,7 +11,7 @@
 # error "Feature-test macro __cpp_lib_spanstrean has wrong value in <iosfwd>"
 #endif
 
-#if __cplusplus >= 202002L && __cpp_lib_syncbuf != 201803L
+#if __cplusplus >= 202002L && _GLIBCXX_USE_CXX11_ABI && __cpp_lib_syncbuf != 201803L
 # error "Feature-test macro __cpp_lib_syncbuf has wrong value in <iosfwd>"
 #endif
 
-- 
2.55.0