early v late bound design and implementation background

[lcnr]

Summary

summarize the status quo of early and late bound lifetimes, things we have to keep in mind going forward, and relevant current implementation details.

Rationale

We currently don't have a shared understanding of the status quo and where we want to go from here. We also don't have any good documentation of this. This meeting should both result in a useful document we can merge into the rustc-dev-guide and a foundation for future discussions, e.g. rust-lang/rust#103448

[BoxyUwU]

Will also be good since the current rustc_dev_guide information on early/late bound lifetimes imo is lacking on information so it will be good to fill that out a bit with stuff from the deep dive doc

[BoxyUwU]

This was scheduled for 10/07/2023

[BoxyUwU]

This deep dive was had here