patch 8.1.1984: 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_python3.vim b/src/testdir/test_python3.vim
index 7f48619..d66e54f 100644
--- a/src/testdir/test_python3.vim
+++ b/src/testdir/test_python3.vim
@@ -54,7 +54,7 @@
 
   try
     py3 f = vim.Function(b'\x80\xfdR' + vim.eval('s:foo()').encode())
-    call assert_equal(name, py3eval('f.name'))
+    call assert_equal(name, 'f.name'->py3eval())
   catch
     call assert_false(v:exception)
   endtry