patch 8.1.1993: 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_charsearch.vim b/src/testdir/test_charsearch.vim
index 17a49e0..6f09e85 100644
--- a/src/testdir/test_charsearch.vim
+++ b/src/testdir/test_charsearch.vim
@@ -20,7 +20,7 @@
   " check that setcharsearch() changes the settings.
   3
   normal! ylfep
-  call setcharsearch({'char': 'k'})
+  eval {'char': 'k'}->setcharsearch()
   normal! ;p
   call setcharsearch({'forward': 0})
   normal! $;p