[libc-commits] [libc] [libc] add IPV6 related macros (PR #162219)

[Michael Jones via libc-commits]

https://github.com/michaelrj-google commented:

I'm not sure if the test is necessary for the macros, given that they're only checking that the value hasn't changed.

https://github.com/llvm/llvm-project/pull/162219