[gcc r16-6203] libstdc++: Fix up all_pedantic_errors.cc

[Jakub Jelinek]

https://gcc.gnu.org/g:932d24f0c705cd647a4f565e41c5dccfaf7b6051

commit r16-6203-g932d24f0c705cd647a4f565e41c5dccfaf7b6051
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Dec 17 09:16:46 2025 +0100

    libstdc++: Fix up all_pedantic_errors.cc
    
    On x86_64-linux I see
    On x86_64-linux
    FAIL: 17_intro/headers/c++1998/all_pedantic_errors.cc  -std=gnu++17 (test for excess errors)
    Excess errors:
    /home/jakub/src/gcc/obj20/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/random.tcc:3681: error: ISO C++ does not support '__int128' for 'type name' [-Wpedantic]
    /home/jakub/src/gcc/obj20/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/random.tcc:3698: error: ISO C++ does not support '__int128' for 'type name' [-Wpedantic]
    This fixes it by adding __extension__.
    
    2025-12-17  Jakub Jelinek  <jakub@redhat.com>
    
            * include/bits/random.tcc (std::generate_canonical): Use
            __extension__ before __generate_canonical_{pow2,any} calls with
            unsigned __int128 template arguments.

Diff:
---
 libstdc++-v3/include/bits/random.tcc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc
index 38e8645c88cb..e102e99eeb22 100644
--- a/libstdc++-v3/include/bits/random.tcc
+++ b/libstdc++-v3/include/bits/random.tcc
@@ -3677,7 +3677,7 @@ namespace __detail
 	    {
 #if defined(__SIZEOF_INT128__)
 	      // Accommodate double double or float128.
-	      return __generate_canonical_pow2<
+	      return __extension__ __generate_canonical_pow2<
 		_RealT, unsigned __int128, __d>(__urng);
 #else
 	      static_assert(false,
@@ -3694,7 +3694,7 @@ namespace __detail
 #if defined(__SIZEOF_INT128__)
 	      static_assert(__d <= 64,
 		"irregular RNG with float precision >64 is not supported");
-	      return __generate_canonical_any<
+	      return __extension__ __generate_canonical_any<
 		_RealT, unsigned __int128, __d>(__urng);
 #else
 	      static_assert(false, "irregular RNG with float precision"