[@babel/eslint-plugin] better no-undef; static no-undef

[BobVarioa]

Feature Request

• I would like to work on this feature!

Is your feature request related to a problem?
When using static properties on classes their existence doesn't get checked; no-undef doesn't work with static anything.

Describe the solution you'd like
I feel like a simple check to check if it's been defined would be sufficient.

Describe alternatives you've considered.
I don't think this is very applicable in this scenario, but maybe not including it in the first place.

Documentation, Adoption, Migration Strategy
Just a @babel/no-undef.

[babel-bot]

Hey @MasterOfBob777! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite."

[JLHwung]

This issue was fixed in #12370, it will be shipped in Babel 7.13. no-undef will support class properties then.