[gcc r13-4573] libstdc++: Fix some -Wunused warnings in tests

[Jonathan Wakely]

https://gcc.gnu.org/g:f76d7943bb310f8ffaa553badb9c8244d6f5beee

commit r13-4573-gf76d7943bb310f8ffaa553badb9c8244d6f5beee
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Dec 8 11:39:20 2022 +0000

    libstdc++: Fix some -Wunused warnings in tests
    
    libstdc++-v3/ChangeLog:
    
            * include/ext/pb_ds/detail/type_utils.hpp (PB_DS_STATIC_ASSERT):
            Add unused attribute to avoid -Wunused-local-typedef warnings.
            * testsuite/17_intro/tag_type_explicit_ctor.cc: Add pragma to
            ignore -Wunused-variable warnings

Diff:
---
 libstdc++-v3/include/ext/pb_ds/detail/type_utils.hpp      | 3 ++-
 libstdc++-v3/testsuite/17_intro/tag_type_explicit_ctor.cc | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/ext/pb_ds/detail/type_utils.hpp b/libstdc++-v3/include/ext/pb_ds/detail/type_utils.hpp
index 52d05392975..c3db6c93ea6 100644
--- a/libstdc++-v3/include/ext/pb_ds/detail/type_utils.hpp
+++ b/libstdc++-v3/include/ext/pb_ds/detail/type_utils.hpp
@@ -152,7 +152,8 @@ namespace __gnu_pbds
     };
 
 #define PB_DS_STATIC_ASSERT(UNIQUE, E)  \
-    typedef __gnu_pbds::detail::__static_assert_dumclass<sizeof(__gnu_pbds::detail::__static_assert<bool(E)>)> UNIQUE##__static_assert_type
+    typedef __gnu_pbds::detail::__static_assert_dumclass<sizeof(__gnu_pbds::detail::__static_assert<bool(E)>)> \
+      UNIQUE##__static_assert_type __attribute__((__unused__))
 
 #endif
 
diff --git a/libstdc++-v3/testsuite/17_intro/tag_type_explicit_ctor.cc b/libstdc++-v3/testsuite/17_intro/tag_type_explicit_ctor.cc
index 410142d3974..fead30f63c3 100644
--- a/libstdc++-v3/testsuite/17_intro/tag_type_explicit_ctor.cc
+++ b/libstdc++-v3/testsuite/17_intro/tag_type_explicit_ctor.cc
@@ -34,6 +34,8 @@ void f5(std::try_to_lock_t);
 void f6(std::adopt_lock_t);
 #endif
 
+#pragma GCC diagnostic ignored "-Wunused-variable"
+
 int main()
 {
   std::nothrow_t v1;