anchor.diff:  Value instructionValue = info.newInstructionValue(new HReturn(null));
   Value lengthValue = info.newLengthValue(new HReturn(null));
   
  -Range createSingleRange(Value value) => info.newRange(value, value);
  +Range createSingleRange(Value value) => info.newNormalizedRange(value, value);
   
   Range createSingleIntRange(int value) {
     return createSingleRange(info.newIntValue(value));
  
positive.code:     upper = info.newIntValue(upper);
    }
  
    Expect.equals(info.newRange(lower, upper), one - two);
  }
  
  checkNegateRange(Range range, [arg1, arg2]) {
  
negative.code: Range createSingleLengthRange() => createSingleRange(lengthValue);
  
  Range createIntRange(int lower, int upper) {
    return info.newNormalizedRange(
        info.newIntValue(lower), info.newIntValue(upper));
  }
  
  Range createLengthRange(int lower) {
    return info.newNormalizedRange(info.newIntValue(lower), lengthValue);
  }
  
  Range createInstructionRange(int lower) {
    return info.newNormalizedRange(info.newIntValue(lower), instructionValue);
  }
  
  Range instruction = createSingleInstructionRange();
  