func (p *Package) Const(name string) (c *NamedConst) {
	c, _ = p.Members[name].(*NamedConst)
	return
}
func (p *Package) Const(name string) (c *NamedConst) {
	c, _ = p.Members[name].(*NamedConst)
	return
}
// Const returns the package-level constant of the specified name,
// or nil if not found.
//