fix String.match() with non-regex parameter

related to issue #482

There are still some JS incompatibilities that should be fixed:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/match
> The returned Array has an extra input property, which contains the original string that was parsed. In addition, it has an index property, which represents the zero-based index of the match in the string.

I could not figure out where to get the `index` value so added only the fix to not throw the TypeError.
Mind if I ask you to remove this now-unused variable? You can also put the `local so, eo` back in the loop.