[Bug preprocessor/81364] Bogus -Wmultistatement-macros warning

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81364

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
C++ doesn't warn.  The problem is that we shouldn't warn (in the C FE) when a
guard is followed by '{'.