[Bc Break] [Alternative] Drop children class detection

[samsonasik]

Children class detection is usefull, but collect class may cause side effect on performance, so this PR drop it, with caveat for add return type which may cause bug when class has child.

For win-win solution, I skip add return type on abstract class.

FYI: @dorrogeray @staabm @chescos @X-Coder264 @mfn

Trade-off: back to original functionality, that cannot detect child, but set skip on add return type on abstract class which mostly overridden.

Notes:

For limit on final class, that probably needs separate PR for separate discussion, as they will need to check on param type addition rules as well.

[samsonasik]

All checks have passed 🎉 @TomasVotruba you decide ;)

[samsonasik]

Also @nuryagdym FYI

[TomasVotruba]

Thank you for fast work 👏 Let's roll

[chescos]

Thanks! My runtime is back down from 16 minutes to 2 minutes after upgrading from v1.1.0 to v1.1.1.

[TomasVotruba]

@chescos Awesome, glad to hear that 👏