[Bug preprocessor/79346] -Wundef should not warn for standard macros

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79346

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-09-28
                 CC|                            |egallager at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Eric Gallager <egallager at gcc dot gnu.org> ---
Confirmed, although it's pretty easy to work around, just write:

#if defined(__STDC_VERSION__) && __STDC_VERSION__ < 199901L
#endif

instead.