[Bug tree-optimization/89478] missed optimization for lambda expression when variable is uninitialized when declared

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89478

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
I think the uninitialized variable makes the initialization not constexpr (and
indeed gcc/clang complain if you try to declare test constexpr). Then we hit
the well-known missed optimization that gcc is unable to convert a dynamic
initialization into a static initialization even in the most trivial constant
cases.