code: func statFile(path string) (os.FileInfo, error) {
  	gopherjsRoot := filepath.Join(build.Default.GOROOT, "src", "github.com", "gopherjs", "gopherjs")
  	if strings.HasPrefix(path, gopherjsRoot+string(filepath.Separator)) {
  		path = filepath.ToSlash(path[len(gopherjsRoot):])
  		if fi, err := vfsutil.Stat(gopherjspkg.FS, path); err == nil {
  			return fi, nil
  		}
  	}
  	return os.Stat(path)
  }
docs: // statFile returns an os.FileInfo describing the named file.
  // For files in "$GOROOT/src/github.com/gopherjs/gopherjs" directory,
  // gopherjspkg.FS is consulted first.