[libc-commits] [libc] [libc][annex_k] Add Annex K support macros. (PR #163100)

[Michael Jones via libc-commits]

https://github.com/michaelrj-google approved this pull request.

Looks good to me once the question of if the compiler or the library should define the macro is resolved.

https://github.com/llvm/llvm-project/pull/163100