google/traceur-compiler — pull request #444 by arv (2013-11-18 03:19:47+00:00)
Title: Fix code gen for classes so that the stack trace looks nicer.

Wrap runtime calls in parens so that $__class does not show up in stack traces.

Merge $__class and $__classExt into one function.

Restructure the temp vars a bit to provide cleaner stack traces.