Don't show windows with "hidden" XRC attribute at all.

This is better than showing them initially and then hiding them if only
because it avoids the unexpected wxEVT_SHOW events being generated.

Closes #15919.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75757 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/xrc/xmlres.h

@@ -620,7 +620,9 @@ public:
    if (m_instance) \
        variable = wxStaticCast(m_instance, classname); \
    if (!variable) \
-       variable = new classname;
+       variable = new classname; \
+   if (GetBool(wxT("hidden"), 0) == 1) \
+       variable->Hide();
 
 
 // FIXME -- remove this $%^#$%#$@# as soon as Ron checks his changes in!!