Generalise delimited continuations primops to work in ST too

The motivation is the same with continuation primops.

Personally I often wish exceptions-like (early exit) effect when working in ST monad (pure computation). As far as I can tell, prompt and control0 allows me to have that.

One can argue that ST versions of primops are slightly safer than their IO counterparts, because explicit state token restricts the usage, forcing everything to stay in the same State# thread.