Fixes:
[cast] redundant cast
[rawtypes] found raw type
[serial] serializable class has no definition of serialVersionUID
Also suppress warning: auxiliary class TargetLanguageBase in ./inherit_target_language.java should not be accessed from outside its own source file
In particular, do not use com.sun.javadoc deprecated since Java 9 and
finally removed in Java 13, to allow the tests to run under modern JRE.
They don't run under Java 8 and earlier any more, but this shouldn't be
a huge problem nowadays and as SWIG output is independent from the Java
version used, it's enough to test it with modern Java versions.
Note that the tests themselves were changed only in the most minimal
way, to adapt them to the new way of running javadoc (which is now also
integrated into CommentParser itself instead of being duplicated in
every test).
William S Fulton