patch 8.2.1340: some tests fail on Cirrus CI and/or with FreeBSD

Problem:    Some tests fail on Cirrus CI and/or with FreeBSD.
Solution:   Make 'backupskip' empty. Do not run tests as root. Check for
            directory when using viminfo. (Ozaki Kiichi, closes #6596)

.cirrus.yml

@@ -11,6 +11,9 @@ freebsd_12_task:
     - NPROC=$(getconf _NPROCESSORS_ONLN)
     - ./configure --with-features=${FEATURES}
     - make -j${NPROC}
-    - src/vim --version
   test_script:
-    - make test
+    - src/vim --version
+      # run tests as user "cirrus" instead of root
+    - pw useradd cirrus -m
+    - chown -R cirrus:cirrus .
+    - sudo -u cirrus make test