Change the register allocator so that it no longer tracks references...

src/x64/codegen-x64.h

 // Copyright 2009 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 560 matching lines @@
 
   // Methods used to indicate which source code is generated for. Source
   // positions are collected by the assembler and emitted with the relocation
   // information.
   void CodeForFunctionPosition(FunctionLiteral* fun);
   void CodeForReturnPosition(FunctionLiteral* fun);
   void CodeForStatementPosition(Node* node);
   void CodeForSourcePosition(int pos);
 
 #ifdef DEBUG
-  // True if the registers are valid for entry to a block.  There should be
-  // no frame-external references to eax, ebx, ecx, edx, or edi.
+  // True if the registers are valid for entry to a block.  There should
+  // be no frame-external references to (non-reserved) registers.
   bool HasValidEntryRegisters();
 #endif
 
   bool is_eval_;  // Tells whether code is generated for eval.
   Handle<Script> script_;
-  List<DeferredCode*> deferred_;
+  ZoneList<DeferredCode*> deferred_;
 
   // Assembler
   MacroAssembler* masm_;  // to generate code
 
   // Code generation state
   Scope* scope_;
   VirtualFrame* frame_;
   RegisterAllocator* allocator_;
   CodeGenState* state_;
   int loop_nesting_;
@@ skipping 20 matching lines @@
   friend class Reference;
   friend class Result;
 
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_CODEGEN_X64_H_