Function calls with this parameter break when using noImplicitSelf

```ts
function foo(this: unknown, val: unknown) {
  print(this, val)
}

foo(3)
```

In TSTL v1.6.0, when using noImplicitSelf, the `foo(3)` call gets translated to `foo(3)` when it should be translated to `foo(nil, 3)` (the this parameter is explicitly specified).

This doesn't happen in v1.5.0, so I suspect this related to the recent "fix" for noImplicitSelf.