// element bitstream.
func (pw *PkgEncoder) NewEncoder(k RelocKind, marker SyncMarker) Encoder {
	e := pw.NewEncoderRaw(k)
	e.Sync(marker)
	return e
}

// NewEncoderRaw returns an Encoder for a new element within the given
// section.
//
// Most callers should use NewEncoder instead.
func (pw *PkgEncoder) NewEncoderRaw(k RelocKind) Encoder {
	idx := Index(len(pw.elems[k]))
	pw.elems[k] = append(pw.elems[k], "") // placeholder