Enhancement: Improve cyclic dependency check to allow recursive instantiation

[Derisis13]

Hi,

I've started using this language server recently, and it's incredible how sophisticated it is compared to all I've previously tried.
However running the LSP on the codebase I work on, it has come to my attention, that the cyclic dependency resolver is way stricter than what's possible without infinite recursion.

One of my IP cores uses recursive self-instantiation, similar to the code in this stack overflow issue: https://stackoverflow.com/questions/38567544/recursive-self-instantiation-component-vhdl (except he uses configurations and I use if-else generate statements combined with entity instantiations)
I can simulate it with Modelsim and even synthesize it with Quartus, but rust_hdl flags it as an error. (and stops evaluating the instantiated IP)
As far as I know self-instantiation is not against the vhdl standard, so it should be allowed by rust_hdl too.

I don't want to ask the impossible: a quick read on the subject has made it clear that this is an example of the halting problem, and it's impossible to solve. I don't have a good idea of how to handle this structure, maybe there's none. But if nothing else, the cyclic dependency could be "demoted" to a warning and the recursed entity analyzed as a black box. This would allow analysis of the IPs that are instantiating the recursive entity.

[Lukas Scheller]

Could you provide a minimal reproducible example? The code in the answer doesn't cause an error for me