Assertion failure when using list in hphpd with same-named function and class

In test.php:

``` hack
run
Program test.php exited normally.
hphpd> list Bloo

Assertion failure: hphp/runtime/debugger/cmd/cmd_list.cpp:186: listFunctionOrClass: assertion `info.size() == 1' failed.
```

I think hphpd already has infrastructure to offer a choice between options, which is probably what we should do here.