[libc-commits] [libc] [libc] Set default visibility for LLVM functions (PR #116686)

[Nick Desaulniers via libc-commits]

https://github.com/nickdesaulniers approved this pull request.

Thanks! This produces the visibility for the non-namespeaced symbols that was accidentally regressed by 5ff3ff33ff930e4ec49da7910612d8a41eb068cb.

Though, I do wonder if the diff I proposed in https://github.com/llvm/llvm-project/issues/74881#issue-2033161156 perhaps would have been a smaller incision than 665efe896746b1dd138773e6e4d300ec97de27c2  + 5ff3ff33ff930e4ec49da7910612d8a41eb068cb ?

One potential issue with this patch might be that users who do use `-DLLVM_LIBC_FUNCTION_ATTR` may be surprised that they may need to re-set default visibility.

We probably should document `LLVM_LIBC_FUNCTION_ATTR` on https://libc.llvm.org/configure.html.

https://github.com/llvm/llvm-project/pull/116686