[committed] libstdc++: Do not check exception at compile-time for mdspan::at for cow string.

[Tomasz Kamiński]

Do not test the exception at compile time if _GLIBCXX_USE_CXX11_ABI
is not set, i.e. standard exceptions types are not supported.

libstdc++-v3/ChangeLog:

        * testsuite/23_containers/mdspan/at.cc: Updated test.
---
Tested on x86_64-linux. Pushed to trunk.

 libstdc++-v3/testsuite/23_containers/mdspan/at.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libstdc++-v3/testsuite/23_containers/mdspan/at.cc 
b/libstdc++-v3/testsuite/23_containers/mdspan/at.cc
index 4e659f57275..d9edce464ad 100644
--- a/libstdc++-v3/testsuite/23_containers/mdspan/at.cc
+++ b/libstdc++-v3/testsuite/23_containers/mdspan/at.cc
@@ -89,6 +89,12 @@ template<typename Int, bool ValidForPacks, bool 
ValidForArrays>
       }
     };
 
+#if !_GLIBCXX_USE_CXX11_ABI
+    if consteval {
+      return true;
+    }
+#endif
+
     verify_throw(-1, 0, 0);
     verify_throw(0, -3, 0);
     verify_throw(0, 0, -5);
-- 
2.53.0