Moved zones and zone related stuff in its own directory.

src/signature.h

 // Copyright 2015 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_SIGNATURE_H_
 #define V8_SIGNATURE_H_
 
-#include "src/zone.h"
+#include "src/zone/zone.h"
 
 namespace v8 {
 namespace internal {
 
 // Describes the inputs and outputs of a function or call.
 template <typename T>
 class Signature : public ZoneObject {
  public:
   Signature(size_t return_count, size_t parameter_count, const T* reps)
       : return_count_(return_count),
@@ skipping 54 matching lines @@
  protected:
   size_t return_count_;
   size_t parameter_count_;
   const T* reps_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_SIGNATURE_H_