Too complex completion in SwiftUI result builder

[hamishknight]

The following completion is too complex:

import SwiftUI

struct S: Identifiable {
  var name: String
  var id: ObjectIdentifier
}

struct V: View {
  var xs: [S] = []

  var body: some View {
    List {
      ForEach(self.xs) { x in
        Group {
          ForEach(self.xs) { y in
            NavigationLink(destination: Text(y.name)) {
              Text(y.#^CC^#)
            }
          }
        }
      }
    }
  }
}

It type-checks quickly if you replace y.#^CC^# with y.name though

[hamishknight]

#84036 makes this no longer too complex, but it still takes tens of seconds to finish