[committed] libstdc++: Add comment about use of always_inline attributes [PR111050]

[Jonathan Wakely]

Add a comment referencing PR 111050, to ensure the fix made by
r12-9903-g1be57348229666 doesn't get reverted.

libstdc++-v3/ChangeLog:

        PR libstdc++/111050
        * include/bits/hashtable_policy.h (_Hash_node_value_base): Add
        comment about always_inline attributes.
---

Tested x86_64-linux. Pushed to trunk.

 libstdc++-v3/include/bits/hashtable_policy.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libstdc++-v3/include/bits/hashtable_policy.h 
b/libstdc++-v3/include/bits/hashtable_policy.h
index 1fa8c01d5e86..76fbc0d3b024 100644
--- a/libstdc++-v3/include/bits/hashtable_policy.h
+++ b/libstdc++-v3/include/bits/hashtable_policy.h
@@ -310,6 +310,8 @@ namespace __detail
 
       __gnu_cxx::__aligned_buffer<_Value> _M_storage;
 
+      // These member functions must be always_inline, see PR 111050
+
       [[__gnu__::__always_inline__]]
       _Value*
       _M_valptr() noexcept
-- 
2.48.1