lwres_hstrerror(3) on macOS

The text a29375e8ae5f, as Mac OS X 10.4.11.x86, Mac OS X 10.4.11.ppc, Mac OS X 10.4.10.x86, Mac OS X 10.4.10.ppc shipped it.

lightweight resolver error message generation

lwres_hstrerror(3) on macOS now