Add regression test for type inference scala#22713

Author: WojciechMazur

tests/pos/i22713.scala

@@ -0,0 +1,13 @@
+import java.util.concurrent.ScheduledExecutorService
+import java.util.concurrent.TimeUnit
+
+def Test = {
+  val worker: ScheduledExecutorService = ???
+  object Worker extends Runnable {
+    def fails(): Either[Exception, Unit] = Right(worker.schedule(this, 5, TimeUnit.NANOSECONDS))
+    def works(): Either[Exception, Unit] = Right {
+      worker.schedule(this, 5, TimeUnit.NANOSECONDS); ()
+    }
+    def run(): Unit = ???
+  }
+}