patch 8.2.1326: Vim9: skipping over white space after list

Problem:    Vim9: skipping over white space after list.
Solution:   Do not skip white space, a following [] would be misinterpreted.
            (closes #6552)  Fix a few side effects.
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 9aa830b..7aaeeb7 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1355,7 +1355,7 @@
   func! Tcomplete(arglead, cmdline, pos)
     return "item1\nitem2\nitem3"
   endfunc
-  call feedkeys(":let c = input('Q? ', '' , 'custom,Tcomplete')\<CR>"
+  call feedkeys(":let c = input('Q? ', '', 'custom,Tcomplete')\<CR>"
         \ .. "\<C-A>\<CR>", 'xt')
   delfunc Tcomplete
   call assert_equal('item1 item2 item3', c)