Specify reserve_space_for_menu in create_prompt_application.

IPython/terminal/ptshell.py

@@ -194,6 +194,7 b' class TerminalInteractiveShell(InteractiveShell):'
                             enable_history_search=True,
                             style=style,
                             mouse_support=self.mouse_support,
+                            reserve_space_for_menu=6,
         )
 
         self.pt_cli = CommandLineInterface(app,