:RInlineTemp does not work if the local variable is assigned again

On the first line of:

```
x = 5
foo = x + 10
x = 10
bar = x + 10
```

Doing RInlineTemp gives me:

```
foo = x + 10
5 = 10
bar = x + 10
```

It should result in the following:

```
foo = 5 + 10
x = 10
bar = x + 10
```
