Virtualize boolean `!` instead of previous desugaring

Virtualize boolean `!` instead of previous desugaring

Summary:
This diff changes the previous strategy for desugaring boolean not `!`.

Previously, we were not virtualizing for typechecking. And we were previously desugaring for runtime:

```
Example`!$my_bool`;
```
to
```
(Example $v) ==> {
  return $v->exclamationMark(..., $v->localVar(..., '$my_bool');
}
```

Now, we will do the following, we will virtualize for typechecking:

```
`$my_bool->__exclamationMark()`
```

And the following for runtime:

```
(Example $v) ==> {
  return $v->methCall(
    ...
    $v->localVar(..., '$my_bool'),
    '__exclamationMark',
    vec[],
  );
}
```

Reviewed By: Wilfred

Differential Revision: D24878303

fbshipit-source-id: 406d637bc54879d7ec1097d99ead785f2416e5e9