code: func (f *flowBuf) put(cond bool, term bool, jumps []*uint) {
  	pc := f.cb.nextPC()
  	if ent, ok := f.ents[pc]; ok {
  		log.Panicf("Flow entry already exists at PC %d: %+v", pc, ent)
  	}
  	f.ents[pc] = &flowEnt{cond, term, jumps, false}
  }
docs: // put creates a flow control point for the next PC in the code buffer.
  // This should be done before pushing the instruction into the code buffer.