Constructors of ES classes require `new` but the runtime doesn't check it

In ES2015+, calling constructors of classes and builtin classes (Map, Set, WeakMap and WeakSet) without `new` throws `TypeError`.
```js
Map(); // throws `TypeError`
```
> https://www.ecma-international.org/ecma-262/6.0/#sec-map-iterable

In Closure Compiler `ADVANCED` mode, `JSC_CONSTRUCTOR_NOT_CALLABLE` warning is correctly thrown in compile time.
But in `SIMPLE` or `WHITESPACE_ONLY` mode, no warnings are detected in compile time and the runtime doesn't throw any errors.

Should the polyfill runtime of Closure Compiler for the constructors throw runtime error for `SIMPLE` and `WHITESPACE_ONLY` mode?

I will send a PR if necessary.