Revert "Move precompilation-related flags to flags list."

runtime/vm/pages.h

 // Copyright (c) 2011, 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_PAGES_H_
 #define VM_PAGES_H_
 
 #include "vm/freelist.h"
 #include "vm/globals.h"
 #include "vm/lockers.h"
 #include "vm/ring_buffer.h"
 #include "vm/spaces.h"
 #include "vm/thread.h"
 #include "vm/virtual_memory.h"
 
 namespace dart {
 
+DECLARE_FLAG(bool, collect_code);
 DECLARE_FLAG(bool, log_code_drop);
 DECLARE_FLAG(bool, always_drop_code);
 DECLARE_FLAG(bool, write_protect_code);
 
 // Forward declarations.
 class Heap;
 class JSONObject;
 class ObjectPointerVisitor;
 
 // A page containing old generation objects.
@@ skipping 420 matching lines @@
   friend class HeapIterationScope;
   friend class PageSpaceController;
   friend class SweeperTask;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PageSpace);
 };
 
 }  // namespace dart
 
 #endif  // VM_PAGES_H_