[Bug tree-optimization/122986] -Wmaybe-uninitialized warnings occur with -O2, but not O1 or O3

[wickedsmoke at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122986

--- Comment #3 from Karl Robillard <wickedsmoke at users dot sourceforge.net> ---
So there is no aliasing violation warning?  Saying the value is uninitialized
is a bit of a red herring.  And having it not be emitted regardless of
optimization level is even more confusing.