// It returns the string as a byte slice, or nil if b is too short to contain the length or
// the full string.
//
//go:nosplit
func gstringb(b []byte) []byte {
	if len(b) < 2 {
		return nil
	}
	n, b := gbit16(b)
	if int(n) > len(b) {
		return nil
	}
	return b[:n]
}

// Offset of the name field in a 9P directory entry - see UnmarshalDir() in dir_plan9.go
const nameOffset = 39