Iirc Oleg Kiselyov implemented proper delimited continuations in ocaml as a library, without touching the runtime or compiler. Something similar has been done in Haskell.
I doubt fully dependent types can be implemented in Haskell without extra help by ghc. There has been lots of work in the area, and last time I checked you could simulate DT to some degree, but it never was as powerful as the dependant types in idris. Iirc t were some edge cases where the typing became undecidable.