Proxyable TypedArray

[森建]

Hi there!

Proxy of TypedArray doesn't have [[TypedArrayName]] and  
[[ViewedArrayBuffer]] slots. so maybe, [22.2.3.5.1  
ValidateTypedArray](http://www.ecma-international.org/ecma-262/7.0/#sec-validatetypedarray)  
throws TypeError like following code.

```js
const uint8 = new Uint8Array([1, 2, 3, 4]);

const proxy = new Proxy(uint8, {});

proxy.map(e => e + 1); // -> TypeError

for(const val of proxy) {
   console.log(val); // -> TypeError
}
```

Is this behavior taken into account?