Use a dictionary-mode code cache on the map rather than a dual system.

src/ic/x64/handler-compiler-x64.cc

 // 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ic/handler-compiler.h"
 
 #include "src/api-arguments.h"
 #include "src/field-type.h"
@@ skipping 738 matching lines @@
   }
   __ Push(name);
   __ Push(value());
   __ Push(Smi::FromInt(language_mode));
   __ PushReturnAddressFrom(scratch1());
 
   // Do tail-call to the runtime system.
   __ TailCallRuntime(Runtime::kStoreCallbackProperty);
 
   // Return the generated code.
-  return GetCode(kind(), Code::FAST, name);
+  return GetCode(kind(), name);
 }
 
 
 Register NamedStoreHandlerCompiler::value() {
   return StoreDescriptor::ValueRegister();
 }
 
 
 Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
     Handle<PropertyCell> cell, Handle<Name> name, bool is_configurable) {
@@ skipping 21 matching lines @@
   Counters* counters = isolate()->counters();
   __ IncrementCounter(counters->ic_named_load_global_stub(), 1);
   if (IC::ICUseVector(kind())) {
     DiscardVectorAndSlot();
   }
   __ ret(0);
 
   FrontendFooter(name, &miss);
 
   // Return the generated code.
-  return GetCode(kind(), Code::NORMAL, name);
+  return GetCode(kind(), name);
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64