test-arbitraryfilectx: stabilize for Windows
Previously, the second last test (context.arbitraryfilectx(..)) returned True on
Windows. I changed the repo setup sequence to import a patch, so that way the
repo would have a proper symlink. That made the last test fail, since it is
comparing files in wdir(), one of which is not the expected symlink.
Apparently the (feature !) line matching doesn't work well with (no-eol), so I
had to conditionalize the test instead of the output.
ERROR: FIXME: This is a known failure of filelog.size for data starting with \1\n
OK.