RFR 8184961: jdk.test.lib.util.FileUtils.deleteFileWithRetry0 should wait for absence of a file

[Andrey Nazarov]

Hi,

Could you review fix in test library which should help to resolve intermittent 
issues on Windows machines during directories clean up. 
  
Bug: https://bugs.openjdk.java.net/browse/JDK-8184961 
<https://bugs.openjdk.java.net/browse/JDK-8184961>
Review: http://cr.openjdk.java.net/~anazarov/JDK-8184961/webrev.00/webrev/


—Andrei