if !Equal(buf.Bytes(), b) {
		t.Fatalf("incorrect result from WriteRune: %q not %q", buf.Bytes(), b)
	}

	p := make([]byte, utf8.UTFMax)
	// Read it back with ReadRune
	for r := rune(0); r < NRune; r++ {
		size := utf8.EncodeRune(p, r)
		nr, nbytes, err := buf.ReadRune()
		if nr != r || nbytes != size || err != nil {
			t.Fatalf("ReadRune(%U) got %U,%d not %U,%d (err=%s)", r, nr, nbytes, r, size, err)
		}

}

type dumper struct {
	w          io.Writer
	rightChars [18]byte
	buf        [14]byte
	used       int  // number of bytes in the current line
	n          uint // number of bytes, total
	closed     bool
}

func toChar(b byte) byte {
	if b < 32 || b > 126 {
		return '.'
	}
	return b
}

func (h *dumper) Write(data []byte) (n int, err error) {
	if h.closed {

	_ sys.NotInHeap
	x uint8
}

// bytep returns a pointer to the n'th byte of b.
func (b *gcBits) bytep(n uintptr) *uint8 {
	return addb(&b.x, n)
}

// bitp returns a pointer to the byte containing bit n and a mask for
// selecting that bit from *bytep.
func (b *gcBits) bitp(n uintptr) (bytep *uint8, mask uint8) {
	return b.bytep(n / 8), 1 << (n % 8)
}

			var stats string
			if logMemStats {
				var mEnd runtime.MemStats
				runtime.ReadMemStats(&mEnd)
				nBytes := mEnd.TotalAlloc - mStart.TotalAlloc
				nAllocs := mEnd.Mallocs - mStart.Mallocs
				stats = fmt.Sprintf("[%d ns %d allocs %d bytes]", time, nAllocs, nBytes)
			} else {
				stats = fmt.Sprintf("[%d ns]", time)
			}

			if f.Log() {
				f.Logf("  pass %s end %s\n", p.name, stats)

				// the runtime's accounting will be wrong.
				nbytes := int64(npages * pageSize)
				gcController.heapReleased.add(nbytes)
				gcController.heapFree.add(-nbytes)

				stats := memstats.heapStats.acquire()
				atomic.Xaddint64(&stats.committed, -nbytes)
				atomic.Xaddint64(&stats.released, nbytes)
				memstats.heapStats.release()
			}

type mOS struct {
	waitsemacount uint32
	notesig       *int8
	errstr        *byte
	ignoreHangup  bool
}

func closefd(fd int32) int32

//go:noescape
func open(name *byte, mode, perm int32) int32

//go:noescape
func pread(fd int32, buf unsafe.Pointer, nbytes int32, offset int64) int32

//go:noescape
func pwrite(fd int32, buf unsafe.Pointer, nbytes int32, offset int64) int32

}

func commaOrPeriod(b byte) bool {
	return b == '.' || b == ','
}

func parseNanoseconds[bytes []byte | string](value bytes, nbytes int) (ns int, rangeErrString string, err error) {
	if !commaOrPeriod(value[0]) {
		err = errBad
		return
	}
	if nbytes > 10 {
		value = value[:10]
		nbytes = 10
	}
	if ns, err = atoi(value[1:nbytes]); err != nil {
		return
	}

}

var CasGStatusAlwaysTrack = &casgstatusAlwaysTrack

//go:noinline
func PanicForTesting(b []byte, i int) byte {
	return unexportedPanicForTesting(b, i)
}

//go:noinline
func unexportedPanicForTesting(b []byte, i int) byte {
	return b[i]
}

func G0StackOverflow() {
	systemstack(func() {
		g0 := getg()
		sp := getcallersp()

		return bytes.NewBuffer(make([]byte, nBytes)), func() {}, nil
	}

	cases := []struct {
		name             string
		readerFunc       func() (io.Reader, func(), error)
		contentLength    int64
		expectedReadFrom bool
	}{
		{
			name:             "file, length",
			readerFunc:       newFileFunc,
			contentLength:    nBytes,
			expectedReadFrom: true,
		},
		{

			}

			if sbytes != newtonLen {
				errc <- fmt.Errorf("sent %d bytes; expected %d", sbytes, newtonLen)
				return
			}
		}()
	}(ln)

	// Connect to listener to retrieve file and verify digest matches
	// expected.
	c, err := Dial("tcp", ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

	h := sha256.New()
	rbytes, err := io.Copy(h, c)
	if err != nil {
		t.Error(err)