func (s byChildIndex) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }

// IsDWARFEnabledOnAIXLd returns true if DWARF is possible on the
// current extld.
// AIX ld doesn't support DWARF with -bnoobjreorder with version
// prior to 7.2.2.
func IsDWARFEnabledOnAIXLd(extld []string) (bool, error) {
	name, args := extld[0], extld[1:]
	args = append(args, "-Wl,-V")

		switch {
		case ctxt.IsELF:
		case ctxt.HeadType == objabi.Hdarwin:
		case ctxt.HeadType == objabi.Hwindows:
		case ctxt.HeadType == objabi.Haix:
			res, err := dwarf.IsDWARFEnabledOnAIXLd(ctxt.extld())
			if err != nil {
				Exitf("%v", err)
			}
			return res
		default:
			return false
		}
	}

	return true
}