don't check invalid byte literal

Author: Emilgardis

tests/ui/proc-macro/auxiliary/api/parse.rs

@@ -48,7 +48,6 @@ fn test_parse_literal() {
     assert!(".8".parse::<Literal>().is_err());
     assert!("0 1".parse::<Literal>().is_err());
     assert!("'a".parse::<Literal>().is_err());
-    assert!("b'❤'".parse::<Literal>().is_err());
     assert!(" 0".parse::<Literal>().is_err());
     assert!("0 ".parse::<Literal>().is_err());
     assert!("/* comment */0".parse::<Literal>().is_err());