Component deprecation (was: [records] Record updates for Preview/2)

[Dan Smith]

> On Jan 9, 2020, at 10:51 AM, forax at univ-mlv.fr wrote:
> 
> Currently you can not deprecate a record component unlike in Scala or in Kotlin.
> We can either allow @Deprecated or pretend that people will never make mistake, change their mind, specification will never change, etc 

Setting aside implementation details, and whether there's any change to be made here: I'm curious about what you intend a deprecated record component to *mean*. How do you deprecate a single parameter of a constructor? A concrete example could be useful—I can believe there might be something there, but I'm struggling to see it.

A related StackOverflow discussion about deprecated parameters/locals:
https://stackoverflow.com/questions/14627313/what-does-deprecated-mean-on-method-parameters-and-local-variables