[Bug c/64249] Missing warning for if (A) else if (A)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64249

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
https://gcc.gnu.org/ml/gcc-patches/2015-09/msg01200.html