Support matches! with if guard

[cynecx]

rustfmt struggles with matches! and if guards.

fn test() {
    let a = matches!(something.very_very_very.long.even.more.fields, Some(very_long_field_name_name_to_check) if method(very_long_field_name));
}

rustfmt 1.5.1-nightly (c0941dfb 2022-08-21)