v-on object syntax doesn't work with v-if

### Version
3.0.0

### Reproduction link
[https://jsfiddle.net/31Lp4a9d/](https://jsfiddle.net/31Lp4a9d/)







### Steps to reproduce
click on `w/ v-if` button

### What is expected?
alert to work

### What is actually happening?
alert doesn't work