[Bug tree-optimization/60165] "may be used uninitialized" warning with -O3 but not with -O2

[vincent-gcc at vinc17 dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60165

--- Comment #2 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
Well, the code paths in question do not necessarily exist (you could say the
same thing with -O2, where the function is not inlined: there may be some code
paths for which fn1() doesn't initialize c).

Actually the number of "maybe-uninitialized" warnings should decrease when the
optimization level increases, because of additional knowledge, not the
opposite.