[llvm-branch-commits] [libcxx] [libcxxabi] release/19.x: [libc++] Fix broken configuration system-libcxxabi on Apple (#110920) (PR #115892)

[Louis Dionne via llvm-branch-commits]

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

I think this is reasonable to cherry-pick. It's fixing a somewhat more niche use case, but if that's useful to @mgorny I think it makes sense to backport.

https://github.com/llvm/llvm-project/pull/115892