Restore back pointer from Instructions to Code

runtime/vm/raw_object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/raw_object.h"
 
 #include "vm/class_table.h"
 #include "vm/dart.h"
 #include "vm/freelist.h"
 #include "vm/isolate.h"
@@ skipping 538 matching lines @@
       visitor->VisitPointer(&(first + i)->raw_obj_);
     }
   }
   return ObjectPool::InstanceSize(raw_obj->ptr()->length_);
 }
 
 
 intptr_t RawInstructions::VisitInstructionsPointers(
     RawInstructions* raw_obj, ObjectPointerVisitor* visitor) {
   RawInstructions* obj = raw_obj->ptr();
+  if (!Dart::IsRunningPrecompiledCode()) {
+    visitor->VisitPointers(raw_obj->from(), raw_obj->to());
+  }
   return Instructions::InstanceSize(obj->size_);
 }
 
 
 bool RawInstructions::ContainsPC(RawInstructions* raw_instr, uword pc) {
   uword start_pc =
       reinterpret_cast<uword>(raw_instr->ptr()) + Instructions::HeaderSize();
   uword end_pc = start_pc + raw_instr->ptr()->size_;
   ASSERT(end_pc > start_pc);
   return (pc >= start_pc) && (pc < end_pc);
@@ skipping 365 matching lines @@
 intptr_t RawUserTag::VisitUserTagPointers(
     RawUserTag* raw_obj, ObjectPointerVisitor* visitor) {
   // Make sure that we got here with the tagged pointer as this.
   ASSERT(raw_obj->IsHeapObject());
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return UserTag::InstanceSize();
 }
 
 
 }  // namespace dart