Use wxDELETE() and wxDELETEA() when possible.

Use wxDELETE[A]() functions which automatically NULL out their arguments after
deleting them instead of doing it manually.

Closes #9685.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64656 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/main.cpp

@@ -333,8 +333,7 @@ struct wxMSWCommandLineArguments
             free(argv[i]);
         }
 
-        delete [] argv;
-        argv = NULL;
+        wxDELETEA(argv);
         argc = 0;
     }