Support wxICON_PRINT and wxICON_HELP_FOLDER in wxOSX art provider

Map them to the corresponding built-in constants.

Closes #8778.

src/osx/artmac.cpp

@@ -87,6 +87,7 @@ static wxIconBundle wxMacArtProvider_CreateIconBundle(const wxArtID& id)
     ART_MSGBOX(wxART_FLOPPY,      wxICON_FLOPPY,      floppy)
     ART_MSGBOX(wxART_HARDDISK,    wxICON_HARDDISK,    harddisk)
     ART_MSGBOX(wxART_REMOVABLE,   wxICON_REMOVABLE,   removable)
+    ART_MSGBOX(wxART_PRINT,       wxICON_PRINT,       print)
 
     ART_MSGBOX(wxART_DELETE,      wxICON_DELETE,      delete)
 
@@ -96,6 +97,7 @@ static wxIconBundle wxMacArtProvider_CreateIconBundle(const wxArtID& id)
 
     ART_MSGBOX(wxART_HELP_SETTINGS, wxICON_HELP_SETTINGS, htmoptns)
     ART_MSGBOX(wxART_HELP_PAGE,   wxICON_HELP_PAGE,   htmpage)
+    ART_MSGBOX(wxART_HELP_FOLDER,   wxICON_HELP_FOLDER,   htmlfoldr)
 
     return wxNullIconBundle;
 }

src/osx/carbon/icon.cpp

@@ -316,6 +316,14 @@ bool wxIcon::LoadIconFromSystemResource(const wxString& resourceName, int desire
     {
         theId = kGenericDocumentIcon ;
     }
+    else if ( resourceName == wxT( "wxICON_PRINT" ) )
+    {
+        theId = kPrintMonitorFolderIcon;
+    }
+    else if ( resourceName == wxT( "wxICON_HELP_FOLDER" ) )
+    {
+        theId = kHelpFolderIcon;
+    }
 
     if ( theId != 0 )
     {