AssemblerBase does not need remember a Zone. Fix this.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 39 matching lines @@
 
 namespace internal {
 
 struct StatsCounter;
 const unsigned kNoASTId = -1;
 // -----------------------------------------------------------------------------
 // Platform independent assembler base class.
 
 class AssemblerBase: public Malloced {
  public:
-  AssemblerBase(Isolate* isolate, Zone* zone);
+  explicit AssemblerBase(Isolate* isolate);
 
   Isolate* isolate() const { return isolate_; }
   int jit_cookie() { return jit_cookie_; }
 
   // Overwrite a host NaN with a quiet target NaN.  Used by mksnapshot for
   // cross-snapshotting.
   static void QuietNaN(HeapObject* nan) { }
 
-  Zone* zone() const { return zone_; }
-
  private:
   Isolate* isolate_;
   int jit_cookie_;
-  Zone* zone_;
 };
 
 
 // -----------------------------------------------------------------------------
 // Labels represent pc locations; they are typically jump or call targets.
 // After declaration, a label can be freely used to denote known or (yet)
 // unknown pc location. Assembler::bind() is used to bind a label to the
 // current pc. A label can be bound only once.
 
 class Label BASE_EMBEDDED {
@@ skipping 799 matching lines @@
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_