LLDB's TypeSystems: An Unfinished Interface

Well, it's "done". TypeSystemRust has a (semi) working prototype for LLDB 19.x . It doesn't support expressions or MSVC targets (i.e. PDB debug info), and there are a whole host of catastrophic crashes, but it more or less proves what it needs to: Rust's debugging experience can be improved, and there are worthwhile benefits to a working TypeSystem that can't be emulated on other layers of the…