Fix T61446: (second part) Some items in editor and mode selectors are not translatable.

That one is utterly ugly fix really, but unfortunately a proper one
would require some changes to our RNA (or more precisely, pyrna) code,
so that when we subscript a dynamically generated RNA collection, the
item is somehow duplicated (and probably 'assigned' to its py object?),
before the temp RNA array memory is freed...

release/scripts/startup/bl_ui/space_view3d.py

@@ -52,13 +52,22 @@ class VIEW3D_HT_header(Header):
 
         object_mode = 'OBJECT' if obj is None else obj.mode
 
+        # Note: This is actually deadly in case enum_items have to be dynamically generated
+        #       (because internal RNA array iterator will free everything immediately...).
+        # XXX This is an RNA internal issue, not sure how to fix it.
+        # Note: Tried to add an accessor to get translated UI strings instead of manual call
+        #       to pgettext_iface below, but this fails because translated enumitems
+        #       are always dynamically allocated.
         act_mode_item = bpy.types.Object.bl_rna.properties["mode"].enum_items[object_mode]
+        act_mode_i18n_context = bpy.types.Object.bl_rna.properties["mode"].translation_context
 
         row.separator()
 
         sub = row.row()
         sub.ui_units_x = 5.5
-        sub.operator_menu_enum("object.mode_set", "mode", text=act_mode_item.name, icon=act_mode_item.icon)
+        sub.operator_menu_enum("object.mode_set", "mode",
+                               text=bpy.app.translations.pgettext_iface(act_mode_item.name, act_mode_i18n_context),
+                               icon=act_mode_item.icon)
         del act_mode_item
 
         layout.template_header_3D_mode()