Wrapper.isEmpty() returns `false` even when only child has `v-if="false"`

[jonboiser]

Version

1.0.0-beta.12

Reproduction link

https://jsfiddle.net/71nkscL4/10/

Steps to reproduce

1. Mount a component with a subtree similar to <component1><component2 v-if="false" /></component1>
2. Select component1 and call its Component1Wrapper.isEmpty() method.

What is expected?

Component1Wrapper.isEmpty() equals true

What is actually happening?

Component1Wrapper.isEmpty() equals false