Update the test to include a custom function1 type

Author: noti0na1

tests/run/i24573.check

@@ -3,3 +3,4 @@
 3
 42
 hello
+world

tests/run/i24573.scala

@@ -7,6 +7,12 @@ trait Con2[-T] extends (T => Int):
 trait Con3[+R] extends (() => R):
   def apply(): R
 
+trait F1[-T, +R] {
+  def apply(t: T): R
+}
+
+trait SF[-T] extends F1[T, Unit] { def apply(t: T): Unit }
+
 object Test:
   def main(args: Array[String]): Unit =
     val f1: (Int => Unit) = i => println(i)
@@ -23,3 +29,6 @@ object Test:
 
     val c4: Con3[Unit] = () => println("hello")
     c4()
+
+    val f5: SF[String] = s => println(s)
+    f5("world")