[Bug c/94389] __attribute__((warn_unused_result)) will warn if the result is discarded as an optimisation

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94389

--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> ---
The C frontend dumps nothing for -fdump-lang-all, but the C++ frontend
shows (in .002l.raw) that the ?: is optimised to just a constant zero
there, already.