Add test

[Cherry-picked 23c094e]

Author: noti0na1

tests/pos/i23194.scala

@@ -0,0 +1,14 @@
+class R[T] extends annotation.StaticAnnotation
+
+class A[T]:
+  val next: A[T] = null
+  val self: this.type = this
+  val selfnext: this.next.type = this.next
+  def f: (A[T] @R[this.type], A[T] @R[this.next.type]) = ???
+  def g: (A[T] @R[self.type], A[T] @R[selfnext.type]) = ???
+
+class Test:
+  def test =
+    val (a, b) = A[String]().f
+    val (a2, b2) = A[String]().g
+