[libc-commits] [libc] [libc][errno] Use macro instead of system header (PR #91150)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

err...we don't plan to support mips or sparc.  We should not be adding headers for them.  We aren't testing those platforms.

https://github.com/llvm/llvm-project/pull/91150