func newPkgDot(pos token.Pos, pkg, name string) ast.Expr {
	return &ast.SelectorExpr{
		X: &ast.Ident{
			NamePos: pos,
			Name:    pkg,
		},
		Sel: &ast.Ident{
			NamePos: pos,
			Name:    name,
		},
	}
}
func newPkgDot(pos token.Pos, pkg, name string) ast.Expr {
	return &ast.SelectorExpr{
		X: &ast.Ident{
			NamePos: pos,
			Name:    pkg,
		},
		Sel: &ast.Ident{
			NamePos: pos,
			Name:    name,
		},
	}
}
// newPkgDot returns an ast.Expr referring to "pkg.name" at position pos.