patch 8.1.2011: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.  Make the window
            command test faster.
diff --git a/src/testdir/test_viminfo.vim b/src/testdir/test_viminfo.vim
index 306f54d..048ebac 100644
--- a/src/testdir/test_viminfo.vim
+++ b/src/testdir/test_viminfo.vim
@@ -171,7 +171,7 @@
 
   call histdel(':')
   " items go before and after
-  call test_settime(8)
+  eval 8->test_settime()
   call histadd(':', "echo '8'")
   call test_settime(39)
   call histadd(':', "echo '39'")