Always run our fast array builtins.

src/runtime/runtime-array.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.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/code-stubs.h"
 #include "src/conversions-inl.h"
 #include "src/elements.h"
 #include "src/factory.h"
 #include "src/isolate-inl.h"
 #include "src/keys.h"
 #include "src/messages.h"
 #include "src/prototype.h"
 
 namespace v8 {
 namespace internal {
 
-RUNTIME_FUNCTION(Runtime_FinishArrayPrototypeSetup) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, prototype, 0);
-  Object* length = prototype->length();
-  CHECK(length->IsSmi());
-  CHECK(Smi::cast(length)->value() == 0);
-  CHECK(prototype->HasFastSmiOrObjectElements());
-  // This is necessary to enable fast checks for absence of elements
-  // on Array.prototype and below.
-  prototype->set_elements(isolate->heap()->empty_fixed_array());
-  return Smi::kZero;
-}
-
 static void InstallCode(
     Isolate* isolate, Handle<JSObject> holder, const char* name,
     Handle<Code> code, int argc = -1,
     BuiltinFunctionId id = static_cast<BuiltinFunctionId>(-1)) {
   Handle<String> key = isolate->factory()->InternalizeUtf8String(name);
   Handle<JSFunction> optimized =
       isolate->factory()->NewFunctionWithoutPrototype(key, code, true);
   if (argc < 0) {
     optimized->shared()->DontAdaptArguments();
   } else {
@@ skipping 634 matching lines @@
     DCHECK(accessor->HasElement(spread_array, i));
     Handle<Object> element = accessor->Get(spread_array, i);
     result->set(i, *element);
   }
 
   return *result;
 }
 
 }  // namespace internal
 }  // namespace v8