LLVM libunwind is an implementation of the interface defined by the HP libunwind project. It was contributed Apple as a way to enable clang++ to port to platforms that do not have a system unwinder. It is intended to be a small and fast implementation of the ABI, leaving off some features of HP's libunwind that never materialized (e.g. remote unwinding).
acquired package info from repodata DB: repodata/8390c0da22ddc16c781aa703c2acfac103b0bd122455c473c4e72cca702c45f5-primary.sqlite.bz2
Unversioned shared library for LLVM libunwind