[builtins] Migrate ArrayBufferPrototypeByteLength to C++.

src/builtins.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/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/ieee754.h"
@@ skipping 5604 matching lines @@
           : SharedFlag::kShared;
   if (!JSArrayBuffer::SetupAllocatingData(Handle<JSArrayBuffer>::cast(result),
                                           isolate, byte_length, true,
                                           shared_flag)) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewRangeError(MessageTemplate::kArrayBufferAllocationFailed));
   }
   return *result;
 }
 
+// ES6 section 24.1.4.1 get ArrayBuffer.prototype.byteLength
+BUILTIN(ArrayBufferPrototypeGetByteLength) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSArrayBuffer, array_buffer,
+                 "get ArrayBuffer.prototype.byteLength");
+  // TODO(franzih): According to the ES6 spec, we should throw a TypeError
+  // here if the JSArrayBuffer is detached.
+  return array_buffer->byte_length();
+}
 
 // ES6 section 24.1.3.1 ArrayBuffer.isView ( arg )
 BUILTIN(ArrayBufferIsView) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(2, args.length());
   Object* arg = args[1];
   return isolate->heap()->ToBoolean(arg->IsJSArrayBufferView());
 }
 
 
@@ skipping 1071 matching lines @@
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_S
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8