Here there are some informations about what can / should be done to implement this, but I don’t know if the information is stale as of today.
The key is to proceed step by step, implementing one piece after the other and only after some infrastructure is set up. For a feature this big a single giant PR with everything inside is not worth it. Pieces of the infrastructure could even be merged to main before the feature lands if that helps the compiler to be more organized / flexible / simple / structured!