anchor.diff:        // If there are continues in the body, we need a named continue
         // continuation as a join point.
         continueContinuation = new ir.Continuation(updateBuilder._parameters);
  -      if (bodyBuilder.isOpen) continueCollector.addJump(bodyBuilder);
  +      if (innerBodyBuilder.isOpen) continueCollector.addJump(innerBodyBuilder);
         invokeFullJoin(continueContinuation, continueCollector);
       }
       ir.Continuation loopContinuation =
  
positive.code:     state.breakCollectors.add(breakCollector);
      state.continueCollectors.add(continueCollector);
  
      IrBuilder bodyBuilder = condBuilder.makeDelimitedBuilder();
  
      bodyBuilder._enterForLoopBody(closureScope, loopVariables);
  
      buildBody(bodyBuilder);
      assert(state.breakCollectors.last == breakCollector);
      assert(state.continueCollectors.last == continueCollector);
      state.breakCollectors.removeLast();
  
negative.code:     // The CPS translation of
      // [[for (initializer; condition; update) body; successor]] is:
      //
      // _enterForLoopInitializer();
      // [[initializer]];
      // let cont loop(x, ...) =
      //     let prim cond = [[condition]] in
      //     let cont break() = [[successor]] in
      //     let cont exit() = break(v, ...) in
      //     let cont body() =
      //         _enterForLoopBody();
      //         let cont continue(x, ...) =
      //             _enterForLoopUpdate();
      //             [[update]];
      //             loop(v, ...) in
      //         [[body]];
      //         continue(v, ...) in
      //     branch cond (body, exit) in
      // loop(v, ...)
      //
  