Windows: Test that we can create a symlink before the target is created

Windows: Test that we can create a symlink before the target is created

According to Win32 API, you need to specificy whether a symlink
points to a file or directory. These tests suggests a symlink created
for a file, can actually point to a directory. We can also create the
link before the target exists, so at least in this respect Windows
symbolic links appears to work as POSIX links.

On POSIX systems these tests have no relevance.

Change-Id: Id3991a4fc4333087c6f569acf04f503b0a0f170d