inline class should not compile with --source 13

[Remi Forax]

Hi all,
currently if you try to compile with the version 13, you get a fun error message
(because ValueBootstrapMethods is not a class which is a part of the version 13).

bash-4.4$ /usr/jdk/jdk-13-lworld/bin/javac --release 13 Simple.java
Simple.java:1: error: cannot access ValueBootstrapMethods
inline class Simple {
       ^
  class file for java.lang.invoke.ValueBootstrapMethods not found
1 error
Fatal Error: Unable to find method makeBootstrapMethod


I believe it's better to not allow "inline" classes if the source version is not 14.

Rémi