0000000 50 4b 03 04 14 00 00 00 08 00 08 03 64 3c f9 f4
0000010 89 64 48 01 00 00 b8 01 00 00 07 00 00 00 72 2f
0000020 72 2e 7a 69 70 00 25 00 da ff 50 4b 03 04 14 00
0000030 00 00 08 00 08 03 64 3c f9 f4 89 64 48 01 00 00
0000040 b8 01 00 00 07 00 00 00 72 2f 72 2e 7a 69 70 00
0000050 2f 00 d0 ff 00 25 00 da ff 50 4b 03 04 14 00 00
0000060 00 08 00 08 03 64 3c f9 f4 89 64 48 01 00 00 b8
0000070 01 00 00 07 00 00 00 72 2f 72 2e 7a 69 70 00 2f

			r := io.MultiReader(strings.NewReader("abc"), &emptyThenNonEmptyReader{r: strings.NewReader("def"), n: 1})
			br := NewReaderSize(r, size)
			want := func(s string, wantErr error) {
				p := make([]byte, 50)
				n, err := br.Read(p)
				if err != wantErr || n != len(s) || string(p[:n]) != s {
					t.Fatalf("read(%d) = %q, %v, want %q, %v", len(p), string(p[:n]), err, s, wantErr)
				}

	ADDS	R1<<1, RSP, R4                  // e46721ab
	CMP	R1<<2, RSP                      // ff6b21eb
	CMN	R1<<3, RSP                      // ff6f21ab
	ADDS	R1<<1, ZR, R4                   // e40701ab
	ADD	R3<<50, ZR, ZR                  // ffcb038b
	CMP	R4<<24, ZR                      // ff6304eb
	CMPW	$0x60060, R2                    // CMPW	$393312, R2                       // 1b0c8052db00a0725f001b6b