patch 8.2.0002: "dj" only deletes first line of closed fold

Problem:    "dj" only deletes first line of closed fold.
Solution:   Adjust last line of operator for linewise motion. (closes #5354)
diff --git a/src/testdir/test_fold.vim b/src/testdir/test_fold.vim
index 824a4f2..36de136 100644
--- a/src/testdir/test_fold.vim
+++ b/src/testdir/test_fold.vim
@@ -769,3 +769,28 @@
   set fdm& ww&
   bwipe!
 endfunc
+
+func Test_fold_delete_first_line()
+  new
+  call setline(1, [
+	\ '" x {{{1',
+	\ '" a',
+	\ '" aa',
+	\ '" x {{{1',
+	\ '" b',
+	\ '" bb',
+	\ '" x {{{1',
+	\ '" c',
+	\ '" cc',
+	\ ])
+  set foldmethod=marker
+  1
+  normal dj
+  call assert_equal([
+	\ '" x {{{1',
+	\ '" c',
+	\ '" cc',
+	\ ], getline(1,'$'))
+  bwipe!
+  set foldmethod&
+endfunc