[libc] [llvm] [libc][math] Refactor rint-nearbyint family to header-only (PR #195577)

[Muhammad Bassiouni via llvm-commits]

================
@@ -1,4 +1,4 @@
-//===-- Implementation header for atanhf16 ----------------------*- C++ -*-===//
+//w==-- Implementation header for atanhf16 ----------------------*- C++ -*-===//
----------------
bassiounix wrote:

```suggestion
//===-- Implementation header for atanhf16 ----------------------*- C++ -*-===//
```

https://github.com/llvm/llvm-project/pull/195577