[Bug preprocessor/122667] Please provide a way to deprecate macros (like Clang's `#pragma clang deprecate(MACRO)`)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122667

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Well it would be:
```
[[deprecated("ATOMIC_VAR_INIT is depercated in C++20")]] constexpr void
atomic_var_init_depercated(void){}
#define ATOMIC_VAR_INIT(VALUE) {(atomic_var_init_depercated(), (VALUE))}
```

But I don't see any reason for a special pragma here really :).