// always removed. The [File.Comments] list is not changed.
//
// FilterFile reports whether there are any top-level declarations
// left after filtering.
func FilterFile(src *File, f Filter) bool {
	return filterFile(src, f, false)
}

func filterFile(src *File, f Filter, export bool) bool {
	j := 0
	for _, d := range src.Decls {
		if filterDecl(d, f, export) {