Speed up the LookupIterator

src/objects-inl.h

 // 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 1943 matching lines @@
 
 int JSObject::GetHeaderSize() { return GetHeaderSize(map()->instance_type()); }
 
 
 int JSObject::GetHeaderSize(InstanceType type) {
   // Check for the most common kind of JavaScript object before
   // falling into the generic switch. This speeds up the internal
   // field operations considerably on average.
   if (type == JS_OBJECT_TYPE) return JSObject::kHeaderSize;
   switch (type) {
+    case JS_SPECIAL_API_OBJECT_TYPE:
+      return JSObject::kHeaderSize;
     case JS_GENERATOR_OBJECT_TYPE:
       return JSGeneratorObject::kSize;
     case JS_MODULE_TYPE:
       return JSModule::kSize;
     case JS_GLOBAL_PROXY_TYPE:
       return JSGlobalProxy::kSize;
     case JS_GLOBAL_OBJECT_TYPE:
       return JSGlobalObject::kSize;
     case JS_BOUND_FUNCTION_TYPE:
       return JSBoundFunction::kSize;
@@ skipping 5808 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_