Factor out handling of mixed objects preprocessing after migration

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 1341 matching lines @@
 
   FlushNumberStringCache();
   if (FLAG_cleanup_code_caches_at_gc) {
     polymorphic_code_cache()->set_cache(undefined_value());
   }
 
   ClearNormalizedMapCaches();
 }
 
 
+void Heap::MigrateMixedObjectInNewSpaceEpilog(HeapObject* dst) {
+  DCHECK(dst->MayContainMixedValues());
+}
+
+
 // Helper class for copying HeapObjects
 class ScavengeVisitor : public ObjectVisitor {
  public:
   explicit ScavengeVisitor(Heap* heap) : heap_(heap) {}
 
   void VisitPointer(Object** p) { ScavengePointer(p); }
 
   void VisitPointers(Object** start, Object** end) {
     // Copy all HeapObject pointers in [start, end)
     for (Object** p = start; p < end; p++) ScavengePointer(p);
@@ skipping 745 matching lines @@
 
     // Make sure that we do not overwrite the promotion queue which is at
     // the end of to-space.
     DCHECK(!heap->InToSpace(target) ||
            heap->promotion_queue()->IsBelowPromotionQueue(
                heap->new_space()->top()));
 
     // Copy the content of source to target.
     heap->CopyBlock(target->address(), source->address(), size);
 
+    if (target->MayContainMixedValues()) {
+      heap->MigrateMixedObjectInNewSpaceEpilog(target);
+    }
+
     // Set the forwarding address.
     source->set_map_word(MapWord::FromForwardingAddress(target));
 
     if (logging_and_profiling_mode == LOGGING_AND_PROFILING_ENABLED) {
       // Update NewSpace stats if necessary.
       RecordCopiedObject(heap, target);
       heap->OnMoveEvent(target, source, size);
     }
 
     if (marks_handling == TRANSFER_MARKS) {
@@ skipping 4392 matching lines @@
       }
       delete list;
     } else {
       prev = list;
     }
     list = next;
   }
 }
 }
 }  // namespace v8::internal