[Bug libstdc++/118434] std::visit should be updated to handle immediate functions

[de34 at live dot cn via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118434

--- Comment #1 from Jiang An <de34 at live dot cn> ---
Corresponding libc++ issue: https://github.com/llvm/llvm-project/issues/118560