Description:

Clang is out of date and libstdc++ expects C++23 compilers to support P0634R3[1] which is implemented in Clang 16[2].
Essential libstdc++ headers will not compile in C++23 as long as Clang remains out of date.

[1] https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0634r3.html
[2] https://clang.llvm.org/cxx_status.html

Steps to reproduce:

Try to compile the following code with `clang++ --std=c++2b`:

```c++
#include <algorithm>
```

NB: The algorithm header is included in many other STL headers like memory.