Add missing test file T7269

(cherry picked from commit db869e75)

testsuite/tests/deriving/should_compile/T7269.hs

+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE MultiParamTypeClasses, StandaloneDeriving, GeneralizedNewtypeDeriving #-}
+
+module T7269 where
+
+class C (a :: k)
+
+instance C Int
+
+newtype MyInt = MyInt Int deriving C
+
+newtype YourInt = YourInt Int
+deriving instance C YourInt