Attributes on primary constructors (records)

[raffaeler]

I had a very annoying issue using System.Text.Json and records: dotnet/runtime#45373

The main cause is that primary constructors cannot be annotated with an attribute because they are intended to be used on constructors and not type declarations.

BTW This issue is hitting a project so hard that we are thinking to write a custom serializer to support the multitude of types impacted. The proposed solution is not acceptable.

The alternative solution is changing the compiler to allow AttributeTargets.Constructor annotating the type but targeting the primary constructors in order to preserve the semantics.

Thoughts?

[svick]

This is a duplicate of #3650.

[raffaeler]

Sorry, missed that