Weld fails on Google AppEngine, javassist.NotFoundException: javax.servlet.http.HttpSession

When using Weld-Servlet in Google App Engine, Weld Core fails on loading classes.

The new Low Level Javassist Proxy layer require access to the Class as a Resource, this is not possible in Google App Engine.

The TCCL, IsolatedAppClassLoader has access to DevAppServerClassLoader which contains the HttpSession class, and IsolatedAppClassLoader delegates to DevAppServerClassLoader on loadClass. but DevAppServerClassLoader is not set as parent, the delegation is 'manual'.
The problem is, javassist tries to lookup the Class as a Resource, using getResource(...). IsolatedAppClassLoader does not delegate to DevAppServerClassLoader for resources. it tries the standard parent, but parent is null.

Full stack trace: http://pastebin.com/M76trE3A