[libcxx-commits] [libcxx] [libc++] Fix header deprecations (PR #163356)

[Nico Weber via libcxx-commits]

nico wrote:

Oh, that's a very elegant approach!

Any chance we could revert this here until a bit until the clang change is in, so we don't have to block a libc++ update on a clang update? We kind of urgently want to roll in #168894 as it fixes a correctness issue.

I suppose we could add a file called `ciso646` on our end and put it in the include search path first on iOS and put something akin to

```
#pragma clang diagnostic disabled("deprecated-declarations")
#include_next <ciso646>
```

in it, but that feels a bit yucky…

https://github.com/llvm/llvm-project/pull/163356