patch 8.2.0195: some tests fail when run in the GUI

Problem:    Some tests fail when run in the GUI.
Solution:   Make sure the window width is enough.  In the GUI run terminal Vim
            in the terminal, if possible.
diff --git a/src/testdir/check.vim b/src/testdir/check.vim
index 6efa348..6876101 100644
--- a/src/testdir/check.vim
+++ b/src/testdir/check.vim
@@ -1,4 +1,5 @@
 source shared.vim
+source term_util.vim
 
 command -nargs=1 MissingFeature throw 'Skipped: ' .. <args> .. ' feature missing'