Create missing boilerplate for array literals instead of deoptimizing

src/hydrogen-instructions.cc

 // Copyright 2011 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 1209 matching lines @@
       String::cast(*handle())->length() == 0) return false;
   return true;
 }
 
 void HConstant::PrintDataTo(StringStream* stream) {
   handle()->ShortPrint(stream);
 }
 
 
 bool HArrayLiteral::IsCopyOnWrite() const {
-  return boilerplate_object_->elements()->map() == HEAP->fixed_cow_array_map();
+  if (!boilerplate_object_->IsJSObject()) return false;
+  return Handle<JSObject>::cast(boilerplate_object_)->elements()->map() ==
+      HEAP->fixed_cow_array_map();
 }
 
 
 void HBinaryOperation::PrintDataTo(StringStream* stream) {
   left()->PrintNameTo(stream);
   stream->Add(" ");
   right()->PrintNameTo(stream);
   if (CheckFlag(kCanOverflow)) stream->Add(" !");
   if (CheckFlag(kBailoutOnMinusZero)) stream->Add(" -0?");
 }
@@ skipping 863 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal