[gcc r13-6323] libstdc++: Suppress warnings about use of deprecated std::aligned_storage

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:ae390479340ff49873c22cd7a301acbf67eca30b

commit r13-6323-gae390479340ff49873c22cd7a301acbf67eca30b
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Feb 23 17:37:59 2023 +0000

    libstdc++: Suppress warnings about use of deprecated std::aligned_storage
    
    libstdc++-v3/ChangeLog:
    
            * include/ext/aligned_buffer.h (__aligned_buffer): Add
            diagnostic pragmas.

Diff:
---
 libstdc++-v3/include/ext/aligned_buffer.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libstdc++-v3/include/ext/aligned_buffer.h b/libstdc++-v3/include/ext/aligned_buffer.h
index 765d14684f2..dc62dfc8741 100644
--- a/libstdc++-v3/include/ext/aligned_buffer.h
+++ b/libstdc++-v3/include/ext/aligned_buffer.h
@@ -81,6 +81,8 @@ namespace __gnu_cxx
   template<typename _Tp>
     using __aligned_buffer = __aligned_membuf<_Tp>;
 #else
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   // Similar to __aligned_membuf but aligned for complete objects, not members.
   // This type is used in <forward_list>, <future>, <bits/shared_ptr_base.h>
   // and <bits/hashtable_policy.h>, but ideally they would use __aligned_membuf
@@ -118,6 +120,7 @@ namespace __gnu_cxx
       _M_ptr() const noexcept
       { return static_cast<const _Tp*>(_M_addr()); }
     };
+#pragma GCC diagnostic pop
 #endif
 
 } // namespace