Incorrect emit of comment in export declaration

**Original**

``` ts
/* blah0 */
// blah1
// blah2
// blah2
export {Subject} from './Subject'
```

**expect**

``` js
/* blah0 */
// blah1
// blah2
// blah3
var Subject_1 = require("./Subject");
```

**Actual**

``` js
"use strict";
var /* blah0 */
// blah1
// blah2
// blah3
Subject_1 = require("./Subject");
```
