[PATCH]: Still a problem with long classpath on Windows

[Basil Peace]

Hi!

A year ago, a patch fixing problem with long classpath on Windows http://cr.openjdk.java.net/~shade/jmh/long-classpath-2.patch was accepted.
Unfortunately, that patch didn't take into account a situation where a temp directory and classpath files are on different drives.
In this case, Path#relativize doesn't work, and we got exception:
    'other' has different root

See e.g. comments in these issues:
* https://github.com/melix/jmh-gradle-plugin/issues/107
* https://github.com/junit-team/junit5/pull/1548

Proposed patch: https://gist.github.com/grv87/b52af66ea49ad50fdb4c4231be489bc6

--
Best regards,
Basil Peace