assertEquals("", Strings.commonSuffix("xyz", "abcde"));
    assertEquals("", Strings.commonSuffix("xyz", "xyzabc"));
    assertEquals("c", Strings.commonSuffix("abc", "ccccc"));
    assertEquals("aa", Strings.commonSuffix("aa", "aaaaa"));
    assertEquals("abc", Strings.commonSuffix(new StringBuilder("xyzabc"), "xxxabc"));

    // Identical valid surrogate pairs.
    assertEquals(

	{"a☺b☻c☹d", "cx", len("a☺b☻")},
	{"a☺b☻c☹d", "uvw☻xyz", len("a☺b")},
	{"aRegExp*", ".(|)*+?^$[]", 7},
	{dots + dots + dots, " ", -1},
	{"012abcba210", "\xffb", 4},
	{"012\x80bcb\x80210", "\xffb", 3},
	{"0123456\xcf\x80abc", "\xcfb\x80", 10},
}

var lastIndexAnyTests = []BinOpTest{
	{"", "", -1},
	{"", "a", -1},
	{"", "abc", -1},
	{"a", "", -1},
	{"a", "a", 0},
	{"\x80", "\xffb", 0},
	{"aaa", "a", 2},