libunwind: fails to bootstrap with musl

[kampka]

I am probably phrasing this poorly, but when trying to bootstrap an LLVM package set with musl, libunwind fails to build (see below for details).

This used to work with older versions of nixpkgs, eg. rev 942da65 builds fine.
Sadly, the build is broken in typisal nixpkgs ways like infinite recursion errors and the like that are (probably) unrelated but make this issue hard and time-consuming to bisect with brute force, so my hope is that someone more knowledgeable will be able to pinpoint this quicket.

Steps To Reproduce

Steps to reproduce the behavior:

nix-build -E 'with import ./. {overlays = [(final: prev: { llvmPackages = prev.llvmPackages_14; })]; }; pkgs.pkgsMusl.pkgsLLVM.libunwind'

Build log

Make Error at src/CMakeLists.txt:99 (message):
  Compiler doesn't support generation of unwind tables if exception support
  is disabled.  Building libunwind DSO with runtime dependency on C++ ABI
  library is not supported.

For the full build log, see https://gist.github.com/kampka/e4c0e1e3797647ed0061d4f392197e15

Notify maintainers

@primeos @lovek323 @7c6f434c @dtzWill @Ericson2314 @sternenseemann

( picked the list from #171047 , hope thats OK)