patch 8.1.1996: 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_put.vim b/src/testdir/test_put.vim
index afe82f9..225ebd1 100644
--- a/src/testdir/test_put.vim
+++ b/src/testdir/test_put.vim
@@ -41,7 +41,7 @@
   call assert_equal(['Line 3', '', 'Line 1', 'Line2'], getline(1,'$'))
   " clean up
   bw!
-  call setreg('a', a[0], a[1])
+  eval a[0]->setreg('a', a[1])
 endfunc
 
 func Test_put_expr()