The comment of the class JavacParser is not appropriate

The following comment in the class JavacParser is not appropriate.

```
It operates by recursive descent, with code derived
systematically from an LL(1) grammar.
```

The javac parser looks like a LL(K) parser instead of LL(1).

The related discussion:

Jan 2021, https://mail.openjdk.java.net/pipermail/compiler-dev/2021-January/016163.html

May 2021, https://mail.openjdk.java.net/pipermail/compiler-dev/2021-May/016972.html