Add wxEventLoopBase::DoRun().

Call it from public Run() after setting the loop as active and resetting
m_shouldExit flag.

No real changes, just cut down on the code duplication among the ports and
make it easier to implement the upcoming changes. see #10258.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74333 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/evtloop.cpp

@@ -50,13 +50,8 @@ wxGUIEventLoop::wxGUIEventLoop()
     m_exitcode = 0;
 }
 
-int wxGUIEventLoop::Run()
+int wxGUIEventLoop::DoRun()
 {
-    // event loops are not recursive, you need to create another loop!
-    wxCHECK_MSG( !IsRunning(), -1, "can't reenter a message loop" );
-
-    wxEventLoopActivator activate(this);
-
     gtk_main();
 
     OnExit();