trailing comma in object should throw an error when parsing ecmaVersion 3

[LongTengDao]

({ k: 'v', })

This should be an error in ES 3.

Is this an oversight? Or the acorn was designed not so restrictive about version?

[marijnh]

That would be an oversight—we do aim to not accept code when an engine targeting the given language version wouldn't support it. Want to submit a pull request to fix this?

[LongTengDao]

@marijnh I'm not familar enough with acorn source, so I can only fix bugs with thrown error stack when shouldn't, but can't figure out where an error should be thrown but not...

Thank you for your trust and giving me chance to fix that, XD