Improve Illuminate\View\View test coverage

This pull request increases test coverage in `ViewTest` for `Illuminate\View\View`.

Before:

```
\Illuminate\View::View
  Methods:  57.69% (15/26)   Lines:  60.61% ( 40/ 66)
```

After:

```
\Illuminate\View::View
  Methods: 100.00% (26/26)   Lines: 100.00% ( 66/ 66)
```