Mach5 is seeing windows tests failing to clean up workspace for subsequent runs due to pack200 is left running and has a hold of a "rt.jar" and a "test.pack" in the test scratch directory.

Logging on the one of these windows machine, when trying to remove the old test directory, I see these:

rm: cannot remove 'testresults/windows-x64/tier2/JTwork/jdk_test/scratch/8/rt.jar': Device or resource busy
rm: cannot remove 'testresults/windows-x64/tier2/JTwork/jdk_test/scratch/8/test.pack': Device or resource busy

I see pack200 is left hanging and when killed, those files can be deleted.