Create missing boilerplate for array literals instead of deoptimizing

src/hydrogen-instructions.h

 // 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 4184 matching lines @@
 
  private:
   int literal_index_;
   int depth_;
 };
 
 
 class HArrayLiteral: public HMaterializedLiteral<1> {
  public:
   HArrayLiteral(HValue* context,
-                Handle<JSObject> boilerplate_object,
+                Handle<HeapObject> boilerplate_object,
                 int length,
                 int literal_index,
                 int depth)
       : HMaterializedLiteral<1>(literal_index, depth),
         length_(length),
         boilerplate_object_(boilerplate_object) {
     SetOperandAt(0, context);
   }
 
   HValue* context() { return OperandAt(0); }
   ElementsKind boilerplate_elements_kind() const {
-    return boilerplate_object_->GetElementsKind();
+    if (!boilerplate_object_->IsJSObject()) {
+      return FAST_ELEMENTS;
+    }
+    return Handle<JSObject>::cast(boilerplate_object_)->GetElementsKind();
   }
-  Handle<JSObject> boilerplate_object() const { return boilerplate_object_; }
+  Handle<HeapObject> boilerplate_object() const { return boilerplate_object_; }
   int length() const { return length_; }
 
   bool IsCopyOnWrite() const;
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
   virtual HType CalculateInferredType();
 
   DECLARE_CONCRETE_INSTRUCTION(ArrayLiteral)
 
  private:
   int length_;
-  Handle<JSObject> boilerplate_object_;
+  Handle<HeapObject> boilerplate_object_;
 };
 
 
 class HObjectLiteralFast: public HMaterializedLiteral<1> {
  public:
   HObjectLiteralFast(HValue* context,
                      Handle<JSObject> boilerplate,
                      int total_size,
                      int literal_index,
                      int depth)
@@ skipping 220 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_