[libcxx-commits] [libcxx] [libc++] "Always" include_next for non C++ path in stdatomic.h (PR #178463)

[Walter Lee via libcxx-commits]

googlewalt wrote:

> Could you add a test to ensure we're `include_next` in C mode? Something similar to `include_as_c.sh.cpp` should work.

Done.  PTAL.

https://github.com/llvm/llvm-project/pull/178463