Last snapshot bits to get working precompiled hello_world on x64.

runtime/vm/heap.h

 // 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.
 
 #ifndef VM_HEAP_H_
 #define VM_HEAP_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/flags.h"
@@ skipping 218 matching lines @@
 
   // The heap map contains the sizes and class ids for the objects in each page.
   void PrintHeapMapToJSONStream(Isolate* isolate, JSONStream* stream) {
     return old_space_.PrintHeapMapToJSONStream(isolate, stream);
   }
 
   Isolate* isolate() const { return isolate_; }
 
   bool ShouldPretenure(intptr_t class_id) const;
 
+  void SetupInstructionsSnapshotPage(void* pointer, uword size) {
+    old_space_.SetupInstructionsSnapshotPage(pointer, size);
+  }
+
  private:
   class GCStats : public ValueObject {
    public:
     GCStats() {}
     intptr_t num_;
     Heap::Space space_;
     Heap::GCReason reason_;
 
     class Data : public ValueObject {
      public:
@@ skipping 101 matching lines @@
   NoHeapGrowthControlScope();
   ~NoHeapGrowthControlScope();
  private:
   bool current_growth_controller_state_;
   DISALLOW_COPY_AND_ASSIGN(NoHeapGrowthControlScope);
 };
 
 }  // namespace dart
 
 #endif  // VM_HEAP_H_