JsCreateTypedArray has wrong SAL annotation

`JsCreateTypedArray` has the following signature in ChakraCore.h:
```c
CHAKRA_API
JsCreateTypedArray(
_In_ JsTypedArrayType arrayType,
_In_ JsValueRef baseArray,
_In_ unsigned int byteOffset,
_In_ unsigned int elementLength,
_Out_ JsValueRef *result);
```
However, according to the documentation comment just above that, baseArray can legally be `JS_INVALID_REFERENCE` (equivalent to NULL), in which case it creates the backing store on the fly:

```
The base array of the new array. Use JS_INVALID_REFERENCE if no base array.
```

Therefore the annotation for `baseArray` should be `_In_opt_`, not `_In_`. There are probably more like this, but this happened to be one I noticed.