Disambiguate PHP shortform ternary

[jeffrafter]

This should fix #56

The current PHP parsing did not support short from ternary (?:) with an immediate token such as true or false following it. I copied the ruleset from https://github.com/facebook/hhvm/blob/master/hphp/parser/hphp.ll#L515 (except for the maybe states) and tried to implement a better lookahead.

I am not sure I did this in the correct/most efficient way and welcome comments/suggestions.

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[jeffrafter]

I realize this is a PR for an issue that was brought up over a year ago but I am using this as a trial 🎈 to better understand the code base. I was hoping for comments and feedback so I can begin digging into some larger issues. Thanks!

[phooji]

@jeffrafter @aryx It's been a while. Should we merge this?

[aryx]

Can you rebase on a more recent version. Apparently we can't automatically merge your request.

[ghost]

Thank you for reporting this issue and appreciate your patience. We've notified the core team for an update on this issue. We're looking for a response within the next 30 days or the issue may be closed.