cmd/aefix/fix.go
func isTopName(n ast.Expr, name string) bool {
	id, ok := n.(*ast.Ident)
	return ok && id.Name == name && id.Obj == nil
}
func isTopName(n ast.Expr, name string) bool {
	id, ok := n.(*ast.Ident)
	return ok && id.Name == name && id.Obj == nil
}
// isTopName returns true if n is a top-level unresolved identifier with the given name.