Reland "Only use FreeSpace objects in the free list"

src/isolate.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_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <queue>
 #include "include/v8-debug.h"
 #include "src/allocation.h"
@@ skipping 1344 matching lines @@
 #endif
 
   // List of callbacks when a Call completes.
   List<CallCompletedCallback> call_completed_callbacks_;
 
   v8::Isolate::UseCounterCallback use_counter_callback_;
   BasicBlockProfiler* basic_block_profiler_;
 
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;
-  friend class IsolateInitializer;
   friend class OptimizingCompilerThread;
   friend class SweeperThread;
   friend class ThreadManager;
   friend class Simulator;
   friend class StackGuard;
   friend class ThreadId;
   friend class TestMemoryAllocatorScope;
   friend class TestCodeRangeScope;
   friend class v8::Isolate;
   friend class v8::Locker;
@@ skipping 205 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_