Merge pull request scala#5797 from jrudolph/patch-1

Improve List creation in BatchingExecutor

Author: lrytz

src/library/scala/concurrent/BatchingExecutor.scala

@@ -103,7 +103,7 @@ private[concurrent] trait BatchingExecutor extends Executor {
   override def execute(runnable: Runnable): Unit = {
     if (batchable(runnable)) { // If we can batch the runnable
       _tasksLocal.get match {
-        case null => unbatchedExecute(new Batch(List(runnable))) // If we aren't in batching mode yet, enqueue batch
+        case null => unbatchedExecute(new Batch(runnable :: Nil)) // If we aren't in batching mode yet, enqueue batch
         case some => _tasksLocal.set(runnable :: some) // If we are already in batching mode, add to batch
       }
     } else unbatchedExecute(runnable) // If not batchable, just delegate to underlying