patch 8.2.3472: other crashes with empty search pattern not tested

Problem:    Other crashes with empty search pattern not tested.
Solution:   Add a few more test lines. (Dominique Pellé)
diff --git a/src/testdir/test_search.vim b/src/testdir/test_search.vim
index bc2b3ad..bb4e45d 100644
--- a/src/testdir/test_search.vim
+++ b/src/testdir/test_search.vim
@@ -1982,8 +1982,11 @@
 
   let @/ = ""
   set incsearch
-  " this was causing a crash
-  call feedkeys("//\x14", 'xt')
+  " these were causing a crash
+  call feedkeys("//\<C-G>", 'xt')
+  call feedkeys("//\<C-T>", 'xt')
+  call feedkeys("??\<C-G>", 'xt')
+  call feedkeys("??\<C-T>", 'xt')
 endfunc