patch 8.1.1915: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
diff --git a/src/testdir/test_cursor_func.vim b/src/testdir/test_cursor_func.vim
index 0f638b3..fbe7be7 100644
--- a/src/testdir/test_cursor_func.vim
+++ b/src/testdir/test_cursor_func.vim
@@ -22,7 +22,7 @@
   call cursor(3, 0)
   call assert_equal([3, 1, 0, 1], getcurpos()[1:])
   " below last line goes to last line
-  call cursor(9, 1)
+  eval [9, 1]->cursor()
   call assert_equal([4, 1, 0, 1], getcurpos()[1:])
 
   call setline(1, ["\<TAB>"])