Combining array.push() operations

Hello,

as `Array.prototype.push()` has the option to push more than one element at a time, I think it would be a good option to let closure compiler know this, to be able to combine multiple

```
a.push(x); a.push(y); a.push(z);
```

occurrences into one

```
a.push(x,y,z)
```

Thanks Robert