jshell + Bach.java compilation issues

[Christian Stein]

Hi kulla-dev,

I'm still working on Bach.java (Java Shell Builder tool) and today
its compilation stopped working when `jshell Bach.java` is invoked.
Same goes for `/open Bach.java` within a jshell session.

Calling `java Bach.java` (JEP 330) runs successfully for all revisions.

I described the issue in more detail at [1] -- here is the gist:
 - revision from yesterday [2] works
 - revision from today [3] chokes.

Here is the diff [4] of the two revisions.

I tried hard to find the underlying issue...
 - renamed types within Bach.java
 - reduced total file size by
   - removing unused enum constants
   - removing all Javadoc
...to no avail.

What barrier am I hitting here?

Cheers,
Christian

[1] https://github.com/sormuras/bach/issues/43
[2]
https://raw.githubusercontent.com/sormuras/bach/5e7165ef06c26423d8906038f2e061eb6cd8f374/src/bach/Bach.java
[3]
https://raw.githubusercontent.com/sormuras/bach/13cf5eb5a9045ac0158d6da585105d359591ba7f/src/bach/Bach.java
[4]
https://github.com/sormuras/bach/commit/13cf5eb5a9045ac0158d6da585105d359591ba7f