[foreign] RFR 8224478: TestSrcDump fails on Windows

[Jorn Vernee]

Hi,

After recent patch that adds a test that creates a symlink [1]. I'm 
seeing a few test failures.

Creating symlinks is a priviledges action on Windows, so this test fails 
with a FileSystemException, and this in turn seems to cause some other 
tests to fail as well.

Bug: https://bugs.openjdk.java.net/browse/JDK-8224478
Webrev: 
http://cr.openjdk.java.net/~jvernee/panama/webrevs/8224478/webrev.00/

This moves the symlink test into it's own jtreg test file, which uses 
`@requires os.family != "windows"`.

Thanks,
Jorn

[1] : 
https://mail.openjdk.java.net/pipermail/panama-dev/2019-May/005438.html