[Bug c/124830] [13/14 only] c/c-decl.cc Fails to cross compile with C++20 host compiler

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

Drea Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.5
            Summary|c/c-decl.cc Fails to cross  |[13/14 only] c/c-decl.cc
                   |compile with C++20 host     |Fails to cross compile with
                   |compiler                    |C++20 host compiler

--- Comment #7 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Note I don't think this is due to C++20 default compiler just libstdc++ stopped
including some headers earlier and only memory includes locale now; just like
how PR 117771 happened.