Update test

Author: noti0na1

tests/pos-custom-args/captures/i23737.scala

@@ -7,4 +7,8 @@ trait A[T]
 trait B[CC^] extends A[C^{CC}] // error: CC not found
 
 trait D[CC^]:
-  val x: Object^{CC} = ???
+  val x: Object^{CC} = ???
+
+def f(c: C^) =
+  val b = new B[{c}] {}
+  val a: A[C^{c}] = b