[Bug libstdc++/124121] Missed optimization in initialization of std::inplace_vector with std::initializer_list

[tkaminsk at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124121

--- Comment #22 from Tomasz Kamiński <tkaminsk at gcc dot gnu.org> ---
I tried removing start_lifetime_as from _M_init function (leave only consteval
part). This does not seem to be required for GCC/clang. However, I get the same
assembly for function `f()`, so `start_lifetime_as` does not seem to be only
culprit here.