All comments stored in the `comments` property of the `grammar` node.
Comments extracted only if the `extractComments` options set to `true` when you generate parser.
This property is object with mapping start offset of comment to comment object, that looks like:
```js
{
text: 'text in the comment, just after // or /* and before */',
multiline: true|false,// true for /**/ comments, false for // comments
location: location()
}
```
Before this commit, the PEG.js parser always created the AST using a plain JavaSctript object, but allthough simple and effective for the job, this method sacrificies performance slightly.
From now on the parser shall call a Node creator. This should help with performance, as well as in the future move some AST helpers into the new AST functions.
