Add slots in the SC for holding object repossession info.

Author: jnthn

src/pmc/serializationcontext.pmc

@@ -21,13 +21,23 @@ pmclass SerializationContext auto_attrs dynpmc group nqp {
     /* Description (probably the file name) if any. */
     ATTR STRING *description;
 
+    /* Repossession info. The following RIA and RPA have matching indexes, each
+     * representing the integer of an object in our root set along with the SC
+     * that the object was originally from. */
+    ATTR PMC *rep_indexes;
+    ATTR PMC *rep_scs;
+    
     VTABLE void init() {
         PMC *root_objects = Parrot_pmc_new(interp, enum_class_ResizablePMCArray);
         PMC *root_stables = Parrot_pmc_new(interp, enum_class_ResizablePMCArray);
         PMC *root_codes   = Parrot_pmc_new(interp, enum_class_ResizablePMCArray);
+        PMC *rep_indexes  = Parrot_pmc_new(interp, enum_class_ResizableIntegerArray);
+        PMC *rep_scs      = Parrot_pmc_new(interp, enum_class_ResizablePMCArray);
         SET_ATTR_root_objects(interp, SELF, root_objects);
         SET_ATTR_root_stables(interp, SELF, root_stables);
         SET_ATTR_root_codes(interp, SELF, root_codes);
+        SET_ATTR_rep_indexes(interp, SELF, rep_indexes);
+        SET_ATTR_rep_scs(interp, SELF, rep_scs);
         PObj_custom_mark_SET(SELF);
         if (!smo_id)
             smo_id = Parrot_pmc_get_type_str(interp, Parrot_str_new(interp, "SixModelObject", 0));
@@ -38,7 +48,7 @@ pmclass SerializationContext auto_attrs dynpmc group nqp {
     }
 
     VTABLE void mark() {
-        PMC    *root_objects, *root_stables, *root_codes;
+        PMC    *root_objects, *root_stables, *root_codes, *rep_indexes, *rep_scs;
         STRING *handle, *description;
         GET_ATTR_root_objects(interp, SELF, root_objects);
         Parrot_gc_mark_PMC_alive(INTERP, root_objects);
@@ -50,6 +60,10 @@ pmclass SerializationContext auto_attrs dynpmc group nqp {
         Parrot_gc_mark_STRING_alive(INTERP, handle);
         GET_ATTR_description(interp, SELF, description);
         Parrot_gc_mark_STRING_alive(INTERP, description);
+        GET_ATTR_rep_indexes(interp, SELF, rep_indexes);
+        Parrot_gc_mark_PMC_alive(INTERP, rep_indexes);
+        GET_ATTR_rep_scs(interp, SELF, rep_scs);
+        Parrot_gc_mark_PMC_alive(INTERP, rep_scs);
     }
 
     VTABLE PMC* get_pmc_keyed_int(INTVAL idx) {