Turn old space cons strings into regular external strings (not short).

src/heap/heap-inl.h

 // 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.
 
 #ifndef V8_HEAP_HEAP_INL_H_
 #define V8_HEAP_HEAP_INL_H_
 
 #include <cmath>
 
 #include "src/base/platform/platform.h"
@@ skipping 443 matching lines @@
   // asserts here, but check everything explicitly.
   if (obj->map() == one_pointer_filler_map()) return false;
   InstanceType type = obj->map()->instance_type();
   MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
   AllocationSpace src = chunk->owner()->identity();
   switch (src) {
     case NEW_SPACE:
       return dst == src || dst == TargetSpaceId(type);
     case OLD_POINTER_SPACE:
       return dst == src && (dst == TargetSpaceId(type) || obj->IsFiller() ||
-                            (obj->IsExternalString() &&
-                             ExternalString::cast(obj)->is_short()));
+                            obj->IsExternalString());
     case OLD_DATA_SPACE:
       return dst == src && dst == TargetSpaceId(type);
     case CODE_SPACE:
       return dst == src && type == CODE_TYPE;
     case MAP_SPACE:
     case CELL_SPACE:
     case PROPERTY_CELL_SPACE:
     case LO_SPACE:
       return false;
     case INVALID_SPACE:
@@ skipping 304 matching lines @@
 
 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
   for (Object** current = start; current < end; current++) {
     CHECK((*current)->IsSmi());
   }
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_INL_H_