8160220: (fs) Tests in jdk/test/java/nio/file/WatchService leave directory trees behind Summary: Create temporary files by default in a scratch directory. Reviewed-by: alanb, chegar

8080603: Replace Unsafe with VarHandle in java.util.concurrent classes 8153715: Use Unsafe.weakCompareAndSet in java.util.concurrent Reviewed-by: martin, psandoz, rriggs, plevart, dfuchs, shade

8157522: Performance improvements to CompletableFuture Reviewed-by: martin, psandoz, rriggs, plevart, dfuchs