Targets that don't support tail calls will see:

    /home/ci/zig/.zig-cache/o/35dbe82c8e4d49ae5b7d630329568133/tmp.zig:5:5: error: unable to perform tail call: compiler backend 'stage2_llvm' does not support tail calls on target architecture 'powerpc64le' with the selected CPU feature flags

So just run this test on a known-good target.