HPHP::Class::setInterfaceVtables(): assertion `vtableVec[slot].vtable == nullptr' failed.

### HHVM Version

HipHop VM 3.13.1 (dbg)
Compiler: tags/HHVM-3.13.1-0-g4f382ad928a6e2a0607a8dcb251002aca77f11f6
Repo schema: 655b5912cb8136e9df6f9be972153e38ac446e0f

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.4 LTS"
### Standalone code, or other way to reproduce the problem

Let say I have a Laravel 5.1 project, and it compile sucessfully (after removing `class_alias`, `extract`, `compact`, and `get_defined_vars`).

``` bash
$ hhvm --hphp -t hhbc -v AllVolatile=true -v WholeProgram=true --input-list compile.list --output-dir repo-bytecode/ -k1 -l4
```

The portion of the class:

``` php