Loosen static reserved identifiers errors on ambient declarations

I think #12065 just broke the selenium-webdriver definition:
https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/selenium-webdriver/index.d.ts#L2601

An example usage:
```ts
driver.findeElement(By.name('firstname')).sendKeys('Bob');
```

One solution is to loosen the error on ambient declarations?