if pkg := pr.pkgs[idx]; pkg != nil {
		return pkg
	}

	pkg := pr.newReader(pkgbits.RelocPkg, idx, pkgbits.SyncPkgDef).doPkg()
	pr.pkgs[idx] = pkg
	return pkg
}

func (r *reader) doPkg() *types.Package {
	path := r.String()
	switch path {
	case "":
		path = r.p.PkgPath()
	case "builtin":
		return nil // universe
	case "unsafe":