JSDoc support for array destructuring

Currently there is no simple way to annotate destructured array parameters.

I propose a syntax similar to the current destructured objects syntax:

``` javascript
/**
* @param {[x: number, y: number]} randomName
* @return number
*/
function add([x, y]) {
return x + y;
}
```

Due to the nature of destructured arrays, this issue is closely related to [#379](https://github.com/google/closure-compiler/issues/379).