Moved zones and zone related stuff in its own directory.

src/compiler/linkage.h

 // Copyright 2014 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_COMPILER_LINKAGE_H_
 #define V8_COMPILER_LINKAGE_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/frame.h"
 #include "src/compiler/operator.h"
 #include "src/frames.h"
 #include "src/machine-type.h"
 #include "src/runtime/runtime.h"
-#include "src/zone.h"
+#include "src/zone/zone.h"
 
 namespace v8 {
 namespace internal {
 
 class CallInterfaceDescriptor;
 class CompilationInfo;
 
 namespace compiler {
 
 const RegList kNoCalleeSaved = 0;
@@ skipping 407 matching lines @@
   CallDescriptor* const incoming_;
 
   DISALLOW_COPY_AND_ASSIGN(Linkage);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_LINKAGE_H_