Add onScopeIdentifierName callback

[dapetcu21]

Hi. I'm working on a Lua autocomplete package for Atom and I figured I would use luaparse.

In my use case, I need to know which identifier is local to which scope ahead of time, since the parsing might error out at the user's cursor as he's editing. That's why I added this callback, which used together with onCreateScope and onDestroyScope gives me a complete idea about the locality of identifiers without having to wait for the node to fully close (for example, a for i = 1, 10 statement would only tell me about i when the block is closed).

[fstirlitz]

Looks fine. onScopeIdentifierName is a bit stupid name, though. And I'd squash the three commits which add this callback. (Maybe even squash all four.)

[dapetcu21]

So, do you have any suggestion of a name? Maybe onScopeIdentifier?

[fstirlitz]

Maybe onDeclareIdentifier (to match onCreateScope/onDestroyScope) or onLocalDeclaration.

[fstirlitz]

Also, it would be good to add a testcase; there's already one for the other callbacks in test/runner.js.

[fstirlitz]

I went ahead and squashed your commits into two, renaming the callback to onLocalDeclaration along the way (commits ab478b9 and 8a24b63). I've also added a testcase (c82cf9f). Consider it merged.

[dapetcu21]

Oh. Sorry for not answering. I completely forgot about this PR and went on with my life. Thanks! 😄