Split octagon autotuner to separate octagonAnalysis and octagonVars autotuners

[karoliineh]

Solves #1449

[michael-schwarz]

We should start to document what these autotuners do somehow. Maybe we can have some way they are registered and a command line option to get the description of all autotuners like you can get one for the analyses?

[sim642]

We should start to document what these autotuners do somehow. Maybe we can have some way they are registered and a command line option to get the description of all autotuners like you can get one for the analyses?

We don't actually have the analysis descriptions available at runtime. They exist as module documentation in the API docs for now (which isn't too user-friendly but better than none at all).
The command line listing exists for options, but we have so many that it's probably unusable compared to the schema itself.

But documenting the autotuners would definitely be a good idea.
I think for a start there could be a documentation comment in the code, e.g. on its main function that is used in the list of available autotuners.

A separate next step would be to split autotune.ml into individual files (while maintaining git blame history) like the analyses, but that requires a bit of trickery.