Do not rewrite the VM isolate's symbol table during AOT snapshots.

runtime/vm/snapshot.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/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 1419 matching lines @@
   }
 
   const Object& obj = Object::Handle(rawobj);
   FATAL1("Unexpected reference to object in VM isolate: %s\n", obj.ToCString());
   return false;
 }
 
 #undef VM_OBJECT_WRITE
 
 
-// An object visitor which will iterate over all the script objects in the heap
-// and either count them or collect them into an array. This is used during
-// full snapshot generation of the VM isolate to write out all script
-// objects and their accompanying token streams.
-class ScriptVisitor : public ObjectVisitor {
- public:
-  explicit ScriptVisitor(Thread* thread)
-      : objHandle_(Object::Handle(thread->zone())), count_(0), scripts_(NULL) {}
-
-  ScriptVisitor(Thread* thread, const Array* scripts)
-      : objHandle_(Object::Handle(thread->zone())),
-        count_(0),
-        scripts_(scripts) {}
-
-  void VisitObject(RawObject* obj) {
-    if (obj->IsScript()) {
-      if (scripts_ != NULL) {
-        objHandle_ = obj;
-        scripts_->SetAt(count_, objHandle_);
-      }
-      count_ += 1;
-    }
-  }
-
-  intptr_t count() const { return count_; }
-
- private:
-  Object& objHandle_;
-  intptr_t count_;
-  const Array* scripts_;
-};
-
-
 ForwardList::ForwardList(Thread* thread, intptr_t first_object_id)
     : thread_(thread),
       first_object_id_(first_object_id),
       nodes_(),
       first_unprocessed_object_id_(first_object_id) {
   ASSERT(first_object_id > 0);
 }
 
 
 ForwardList::~ForwardList() {
@@ skipping 569 matching lines @@
       *buffer_len_ = BytesWritten();
     }
   } else {
     FreeBuffer();
     ThrowException(exception_type(), exception_msg());
   }
 }
 
 
 }  // namespace dart