[Bug c/67819] -Wduplicated-cond should take macros into account

[mpolacek at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67819

--- Comment #8 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
-Wduplicated-branches has the same problem, see
<https://gcc.gnu.org/legacy-ml/gcc-patches/2016-10/msg01527.html>.