[8u40] Request for approval: JDK-8047935: Adding new API for unlocking diagnostic argument for SharedArchiveFile

[Jiangli Zhou]

Please approve backport of JDK-8047935 
<https://bugs.openjdk.java.net/browse/JDK-8047935> to 8u40. This is a 
clean import of the changesets (for JDK-8047934 
<https://bugs.openjdk.java.net/browse/JDK-8047934>) from JDK9.

Bug: https://bugs.openjdk.java.net/browse/JDK-8047935
Webrev: http://cr.openjdk.java.net/~jiangli/8047935/webrev.00/
Changeset: http://hg.openjdk.java.net/jdk9/hs-rt/hotspot/rev/7845c825b8c7

Thanks,
Jiangli