[libcxx-commits] [libcxxabi] [libcxxabi] Add a missing include for abort() (PR #126865)

[Louis Dionne via libcxx-commits]

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

LGTM. I used `std::abort` instead because `<cstdlib>` is not technically required to provide `::abort`.

https://github.com/llvm/llvm-project/pull/126865