func relName(v Value, i Instruction) string {
	var from *types.Package
	if i != nil {
		from = i.Parent().pkg()
	}
	switch v := v.(type) {
	case Member: // *Function or *Global
		return v.RelString(from)
	case *Const:
		return v.RelString(from)
	}
	return v.Name()
}
func relName(v Value, i Instruction) string {
	var from *types.Package
	if i != nil {
		from = i.Parent().pkg()
	}
	switch v := v.(type) {
	case Member: // *Function or *Global
		return v.RelString(from)
	case *Const:
		return v.RelString(from)
	}
	return v.Name()
}
// relName returns the name of v relative to i.
// In most cases, this is identical to v.Name(), but references to
// Functions (including methods) and Globals use RelString and
// all types are displayed with relType, so that only cross-package
// references are package-qualified.
//