[committed] libstdc++: Fix use of internal feature test macro in test

[Jonathan Wakely]

This test should use __cpp_lib_ios_noreplace rather than the internal
__glibcxx_ios_noreplace macro.

libstdc++-v3/ChangeLog:

        * testsuite/27_io/ios_base/types/openmode/case_label.cc: Use
        standard feature test macro not internal one.
---

Tested x86_64-linux. Pushed to trunk.

 .../testsuite/27_io/ios_base/types/openmode/case_label.cc       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc 
b/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
index 253a0dc75668..e132070bf487 100644
--- a/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
+++ b/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
@@ -44,7 +44,7 @@ case_labels(bitmask_type b)
       break;
     case std::ios_base::trunc:
       break;
-#ifdef __glibcxx_ios_noreplace
+#ifdef __cpp_lib_ios_noreplace
     case std::ios_base::noreplace:
       break;
 #endif
-- 
2.47.1