Pitch: Debug Description macro

In addition to the macro, can we please also expose a straightforward way to simply manually specify the summary string that we want lldb to use, alongside each type?

@_lldbFormatter("${var.id}: ${var.name}")
struct Student: CustomStringConvertible {
  var name: String
  var id: Int

  var description: String {
    // potentially more complicated code than what `@DebugDescription`
    // would be able to handle
  }
}

I understand macros are very awesome, but it isn't always appropriate to rely on heuristic behavior. For instance, I think it would not always be possible to simplify description implementations only to appease a macro.