kripken/emscripten — pull request #265 by adetaylor (2012-02-20 08:56:38+00:00)
Title: Polymorphic exception handling.

Previously exception handling only worked if there were a 'catch' block which precisely matched
the type of the thrown exception.

That's not always the case if we're trying to catch subclasses.

This change enhances behaviour to match subclasses, and also covers some other cases where
we weren't catching the right thing.