Add support for wxALWAYS_SHOW_SB style to wxScrolled<>.

Simply call ShowScrollbars(wxSHOW_SB_ALWAYS) if this style is specified.

Closes #13616.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72621 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/scrolwin.h

@@ -384,6 +384,9 @@ public:
         if ( !(style & (wxHSCROLL | wxVSCROLL)) )
             style |= wxHSCROLL | wxVSCROLL;
 
+        if ( style & wxALWAYS_SHOW_SB )
+            ShowScrollbars(wxSHOW_SB_ALWAYS, wxSHOW_SB_ALWAYS);
+
         return T::Create(parent, winid, pos, size, style, name);
     }