patch 8.2.0194: some commands can cause problems in terminal popup

Problem:    Some commands can cause problems in terminal popup.
Solution:   Disallow more commands.
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index 00f0bfe..7fda9f6 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -2357,7 +2357,7 @@
   call VerifyScreenDump(buf, 'Test_terminal_popup_3', {})
  
   call term_sendkeys(buf, ":q\<CR>")
-  call term_wait(buf, 50)  " wait for terminal to vanish
+  call term_wait(buf, 100)  " wait for terminal to vanish
 
   call StopVimInTerminal(buf)
   call delete('XtermPopup')