entryNames := []string{`/`, `//`, `\`, `/test.txt`}
	var names []string
	for _, f := range r.File {
		names = append(names, f.Name)
		if _, err := f.Open(); err != nil {
			t.Errorf("Error opening %q: %v", f.Name, err)
		}
		if _, err := r.Open(f.Name); err == nil {
			t.Errorf("Opening %q with fs.FS API succeeded", f.Name)
		}
	}
	if !reflect.DeepEqual(names, entryNames) {

			n := &Name{Go: s, C: s}
			names = append(names, n)
			optional[n] = true
		}

		// Otherwise, we'll need to find out from gcc.
		names = append(names, n)
	}

	// Bypass gcc if there's nothing left to find out.
	if len(names) == 0 {
		return needType
	}

	// Coerce gcc into telling us whether each name is a type, a value, or undeclared.
	// For names, find out whether they are integer constants.