[Bug c/28901] -Wunused-variable ignores unused const initialised variables

[andi-gcc at firstfloor dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=28901

--- Comment #17 from Andi Kleen <andi-gcc at firstfloor dot org> ---
There were a few false or useless ones (e.g. related to macros and specific
build configs).  I didn't look through them all, but various were semi
legitimate, but also very minor (small) so fixing it won't help much. I think
one or two of the ones I looked at may have been real bugs.

I still think the warning should not be in -Wall. thousand+ warnings in real
projects is just not acceptable.