Make so that array length property access uses a new IC that tracks the array map.

src/ast.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 405 matching lines @@
     } else if (oracle->LoadIsBuiltin(this, Builtins::kLoadIC_StringLength)) {
       is_string_length_ = true;
     } else if (oracle->LoadIsBuiltin(this,
                                      Builtins::kLoadIC_FunctionPrototype)) {
       is_function_prototype_ = true;
     } else {
       Literal* lit_key = key()->AsLiteral();
       ASSERT(lit_key != NULL && lit_key->handle()->IsString());
       Handle<String> name = Handle<String>::cast(lit_key->handle());
       oracle->LoadReceiverTypes(this, name, &receiver_types_);
+      if (oracle->LoadForeignCallbackType(this) ==
+          Code::ExtraICStateForeignCallbackArrayLength) {
+        is_array_length_ = true;
+      }
     }
   } else if (oracle->LoadIsBuiltin(this, Builtins::kKeyedLoadIC_String)) {
     is_string_access_ = true;
   } else if (is_monomorphic_) {
     receiver_types_.Add(oracle->LoadMonomorphicReceiverType(this),
                         zone);
   } else if (oracle->LoadIsMegamorphicWithTypeInfo(this)) {
     receiver_types_.Reserve(kMaxKeyedPolymorphism, zone);
     oracle->CollectKeyedReceiverTypes(PropertyFeedbackId(), &receiver_types_);
   }
@@ skipping 694 matching lines @@
     OS::SNPrintF(buffer, "%d", Smi::cast(*handle_)->value());
     str = arr;
   } else {
     str = DoubleToCString(handle_->Number(), buffer);
   }
   return FACTORY->NewStringFromAscii(CStrVector(str));
 }
 
 
 } }  // namespace v8::internal