case syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
			prog.Inst[ix].Next = nil
			prog.Inst[ix] = onePassInst{Inst: instOriginal}
		}
	}
}

// onePassCopy creates a copy of the original Prog, as we'll be modifying it.
func onePassCopy(prog *syntax.Prog) *onePassProg {
	p := &onePassProg{
		Start:  prog.Start,
		NumCap: prog.NumCap,
		Inst:   make([]onePassInst, len(prog.Inst)),
	}