func TestFS(t *testing.T) {
	for _, test := range []struct {
		file string
		want []string
	}{
		{
			"testdata/unix.zip",
			[]string{"hello", "dir/bar", "readonly"},
		},
		{
			"testdata/subdir.zip",
			[]string{"a/b/c"},
		},
	} {
		test := test
		t.Run(test.file, func(t *testing.T) {
			t.Parallel()
			z, err := OpenReader(test.file)
			if err != nil {

		{"a☺b☻c☹d", "b", len("a☺")},               // non-ascii
	}
	for _, test := range testCases {
		actual := LastIndexByte([]byte(test.a), test.b[0])
		if actual != test.i {
			t.Errorf("LastIndexByte(%q,%c) = %v; want %v", test.a, test.b[0], actual, test.i)
		}
	}
}

// test a larger buffer with different sizes and alignments
func TestIndexByteBig(t *testing.T) {
	var n = 1024

	FMOVD	0x1006ff8(R1), F2	// FMOVD	16805880(R1), F2	// 3bfc7f9162ff7ffd

// very large or unaligned offset uses constant pool.
// the encoding cannot be checked as the address of the constant pool is unknown.
// here we only test that they can be assembled.
	MOVB	R1, 0x1000000(R2)	// MOVB		R1, 16777216(R2)
	MOVB	R1, 0x44332211(R2)	// MOVB		R1, 1144201745(R2)
	MOVH	R1, 0x1001000(R2)	// MOVH		R1, 16781312(R2)

	// Hex constant 0x20004000000
	MOVD $2199090364416, R5         // 60058001
	// Hex constant 0xFFFFFE0004000000
	MOVD $-2198956146688, R5        // 38a08001
	// TODO: On GOPPC64={power8,power9}, this is preprocessed into MOVD $-1, R5; RLDC R5, $33, $63, R5.
	//       This only captures the MOVD. Should the RLDC be appended to the encoding by the test?
	// Hex constant 0xFFFFFFFE00000001