[libcxx-commits] [libcxx] [DRAFT][libc++][modules] Improves std.compat module. (PR #74945)

[Chuanqi Xu via libcxx-commits]

https://github.com/ChuanqiXu9 commented:

Thanks for the quick action.

I am wondering if we can make this better to remove the duplicated includes completely (like <cmath>). 

For example, is it valid to do the following:

```
export module std.compat;
export import std;

export using double_t = std::double_t;
```

https://github.com/llvm/llvm-project/pull/74945