Add test of carriage return newline in raw string

Author: dtolnay

tests/test.rs

@@ -83,6 +83,11 @@ fn literal_string() {
     assert_eq!(Literal::string("didn't").to_string(), "\"didn't\"");
 }
 
+#[test]
+fn literal_raw_string() {
+    "r\"\r\n\"".parse::<TokenStream>().unwrap();
+}
+
 #[test]
 fn literal_character() {
     assert_eq!(Literal::character('x').to_string(), "'x'");