result should be true, with autofree result is false

**What did you do?**
```v
fn main() {
	mut a := true
	b := a && if true {
		a = false
		true
	} else {
		false
	}
	println(b)
}
```

**What did you expect to see?**
`true`
 
**What did you see instead?**
```
➜  v git:(master) ✗ v run main.v
true
➜  v git:(master) ✗ v -autofree run main.v
false
```