RFR: 8166287: MultiReleaseJarAPI.isMultiReleaseJar(): failure java.nio.file.AccessDeniedException: custom-mr.jar

[Claes Redestad]

Hi,

recently added test cases to MultiReleaseJarAPI can cause an 
AccessDeniedException on some Windows systems, and using a distinct name 
of the jar generated for each test should avoid this.

webrev: http://cr.openjdk.java.net/~redestad/8166287/webrev.01/
bug: https://bugs.openjdk.java.net/browse/JDK-8166287

Since the only hosts I've found where the stars align to cause this 
issue are some used in our nightly hotspot testing, I intend to push 
this to jdk9/hs - unless anyone objects.

Thanks!

/Claes