Add test about F-Bounds

Author: liufengyun

tests/pos/i9740c.scala

@@ -0,0 +1,16 @@
+sealed trait Exp[T]
+case class IntExp(x: Int) extends Exp[Int]
+case class StrExp(x: String) extends Exp[String]
+object UnitExp extends Exp[Unit]
+
+trait Txn[T <: Txn[T]]
+case class Obj(o: AnyRef) extends Txn[Obj] with Exp[AnyRef]
+
+
+class Foo {
+  def bar[A <: Txn[A]](x: Exp[A]): Unit = x match
+    case IntExp(x) =>
+    case StrExp(x) =>
+    case UnitExp =>
+    case Obj(o) =>
+}