facebook/esprima — pull request #42 by mathiasbynens (2014-08-26 21:20:50+00:00)
Title: Support future regular expression flags

This makes Esprima not throw on regular expression literals that use the new `u` and `y` flags in ES6.

This allows [regexpu](https://github.com/mathiasbynens/regexpu) to work.