Negated code points near the surrogate gap still match #1397

#[test]
fn regression_negated_class_across_surrogate_hole() {
    let re = Regex::new(r"^[^\x{D7FF}\x{E000}\x{000A}]$").unwrap();
    
    // This assertion succeeds, 0A is excluded
    assert!(!re.is_match("\u{000A}"), "U+000A is excluded by the class");

    // This succeeds, 0B is INcluded
    assert!(re.is_match("\u{000B}"), "U+000B is included by the class");

    // These two do not
    assert!(!re.is_match("\u{D7FF}"), "U+D7FF is excluded by the class");
    assert!(!re.is_match("\u{E000}"), "U+E000 is excluded by the class");
}