Cleanup the type of UnApply trees in posttyper

[Cherry-picked 170f1ff]

Author: noti0na1

tests/pos/i24207.scala

@@ -0,0 +1,12 @@
+class Generator:
+  private def generateTable(table: Table) =
+    val (ownRelations, _) = calculateOwnRelations(table)
+    ownRelations
+
+  private def calculateOwnRelations(table: Table) =
+    val ownRelations = table.relations.filter(_.association.isDefined)
+    (ownRelations, Nil)
+
+case class Table(relations: Seq[TableRelation])
+case class TableRelation(association: Option[Association])
+trait Association