fix(3242): check class name collisions with Object

[a-tarasyuk]

Fixes #3242

[jakebailey]

I think we actually need something that goes further, like #2087, since there are more checks like this. Though this particular filed issue is fun because it reveals that we were somehow only checking this in non-ESM files.

[jakebailey]

To be clear, that other PR could be overcomplicated, so I'm not saying to close this, rather that there's a wider range of missing code we seem to need.