OutOfMemoryException

Not sure what I'm doing wrong, but replacing your example grammar with one from https://www.npmjs.com/package/pegjs-otf results in OutOfMemory when executing `parser.parse("hello world")`

```js
var grammar = `
sample = _ 

_ "blank"
    = (co / ws)*

co "comment"
    = "//" (![\\r\\n] .)*
    / "/*" (!"*/" .)* "*/"

ws "whitespaces"
    = [ \\t\\r\\n]+
`
```

