patch 8.2.2994: various code is not fully tested

Problem:    Various code is not fully tested.
Solution:   Add a few more tests. (Yegappan Lakshmanan, closes #8378)
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index 2f64d12..2d87920 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -1160,4 +1160,21 @@
   set cmdheight&
 endfunc
 
+" To specify a control character as a option value, '^' can be used
+func Test_opt_control_char()
+  set wildchar=^v
+  call assert_equal("\<C-V>", nr2char(&wildchar))
+  set wildcharm=^r
+  call assert_equal("\<C-R>", nr2char(&wildcharm))
+  " Bug: This doesn't work for the 'cedit' and 'termwinkey' options
+  set wildchar& wildcharm&
+endfunc
+
+" Test for the 'errorbells' option
+func Test_opt_errorbells()
+  set errorbells
+  call assert_beeps('s/a1b2/x1y2/')
+  set noerrorbells
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab