Move a bunch of GC related files to heap/ subdirectory

src/handles-inl.h

 // Copyright 2006-2008 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_HANDLES_INL_H_
 #define V8_HANDLES_INL_H_
 
 #include "src/api.h"
 #include "src/handles.h"
-#include "src/heap.h"
+#include "src/heap/heap.h"
 #include "src/isolate.h"
 
 namespace v8 {
 namespace internal {
 
 template<typename T>
 Handle<T>::Handle(T* obj) {
   location_ = HandleScope::CreateHandle(obj->GetIsolate(), obj);
 }
 
@@ skipping 152 matching lines @@
   current->level = level_;
   DCHECK_EQ(current->next, current->limit);
   current->limit = limit_;
 }
 
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_INL_H_