Revert of Disallow subclassing Arrays.

src/x64/builtins-x64.cc

 // Copyright 2012 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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
@@ skipping 1254 matching lines @@
     // Initial map for the builtin Array functions should be maps.
     __ movp(rbx, FieldOperand(rdi, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     STATIC_ASSERT(kSmiTag == 0);
     Condition not_smi = NegateCondition(masm->CheckSmi(rbx));
     __ Check(not_smi, kUnexpectedInitialMapForArrayFunction);
     __ CmpObjectType(rbx, MAP_TYPE, rcx);
     __ Check(equal, kUnexpectedInitialMapForArrayFunction);
   }
 
-  __ movp(rdx, rdi);
   // Run the native code for the Array function called as a normal function.
   // tail call a stub
   __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
   ArrayConstructorStub stub(masm->isolate());
   __ TailCallStub(&stub);
 }
 
 
 void Builtins::Generate_StringConstructCode(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ skipping 329 matching lines @@
   __ bind(&ok);
   __ ret(0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64