Casted receiver negation of `instanceof` completions

Consider completion at `|`:

```java
if (!(node instanceof MethodDeclaration) || node.getB|) {
System.out.println("Hello, World!");
}
```

I think it would be reasonable to suggest:

```java
if (!(node instanceof MethodDeclaration) || ((MethodDeclaration)node).getBody()|) {
System.out.println("Hello, World!");
}
```

I don't know how difficult this would be to implement.