patch 8.2.0509: various code is not properly tested.

Problem:    various code is not properly tested.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #5871)
diff --git a/src/testdir/check.vim b/src/testdir/check.vim
index 22c33c0..34bf5b3 100644
--- a/src/testdir/check.vim
+++ b/src/testdir/check.vim
@@ -133,3 +133,13 @@
     throw 'Skipped: cannot run test as root'
   endif
 endfunc
+
+" Command to check that the current language is English
+command CheckEnglish call CheckEnglish()
+func CheckEnglish()
+  if v:lang != "C" && v:lang !~ '^[Ee]n'
+      throw 'Skipped: only works in English language environment'
+  endif
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab