func (t *Type) Obj() Object {
	return t.obj
}

// SetUnderlying sets the underlying type of an incomplete type (i.e. type whose kind
// is currently TFORW). SetUnderlying automatically updates any types that were waiting
// for this type to be completed.
func (t *Type) SetUnderlying(underlying *Type) {
	if underlying.kind == TFORW {
		// This type isn't computed yet; when it is, update n.