Seems to be JIT optimization problem

###### Version

chakra-1.11.24.0, 1.13.0.0-beta

###### Test case 1

```js
var a;
for(let b = 30000;b>-1;b--){
a = b * -1
a += a ;
}
print(Object.is(a, 0));
print(Object.is(a, -0));
```

###### Execution steps 1

.ch Testcase.js

###### Output 1
```
true
false
```

###### Expected result 1
```
false
true
```

###### Test case 2

```js
var a;
for(let b = 30;b>-1;b--){
a = b * -1
a += a ;
}
print(Object.is(a, 0));
print(Object.is(a, -0));
```

###### Execution steps 2

.ch Testcase.js

###### Output 2
```
false
true
```

###### Expected result 1
```
false
true
```

###### Description

When the number of cycles increases, chakra outputs the wrong result.It seems to be caused by incorrect JIT optimization.