Compile FastCloneShallowObjectStub using Crankshaft.

src/hydrogen-instructions.h

 // 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 103 matching lines @@
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(GlobalObject)                              \
   V(GlobalReceiver)                            \
   V(Goto)                                      \
   V(HasCachedArrayIndexAndBranch)              \
   V(HasInstanceTypeAndBranch)                  \
   V(In)                                        \
   V(InstanceOf)                                \
   V(InstanceOfKnownGlobal)                     \
+  V(InstanceSize)                              \
   V(InvokeFunction)                            \
   V(IsConstructCallAndBranch)                  \
   V(IsNilAndBranch)                            \
   V(IsObjectAndBranch)                         \
   V(IsStringAndBranch)                         \
   V(IsSmiAndBranch)                            \
   V(IsUndetectableAndBranch)                   \
   V(JSArrayLength)                             \
   V(LeaveInlined)                              \
   V(LoadContextSlot)                           \
@@ skipping 3480 matching lines @@
 
   virtual HType CalculateInferredType();
 
   DECLARE_CONCRETE_INSTRUCTION(InstanceOfKnownGlobal)
 
  private:
   Handle<JSFunction> function_;
 };
 
 
+// TODO(mstarzinger): This instruction should be modeled as a load of the map
+// field followed by a load of the instance size field once HLoadNamedField is
+// flexible enough to accommodate byte-field loads.
+class HInstanceSize: public HTemplateInstruction<1> {
+ public:
+  explicit HInstanceSize(HValue* object) {
+    SetOperandAt(0, object);
+    set_representation(Representation::Integer32());
+  }
+
+  HValue* object() { return OperandAt(0); }
+
+  virtual Representation RequiredInputRepresentation(int index) {
+    return Representation::Tagged();
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(InstanceSize)
+};
+
+
 class HPower: public HTemplateInstruction<2> {
  public:
   HPower(HValue* left, HValue* right) {
     SetOperandAt(0, left);
     SetOperandAt(1, right);
     set_representation(Representation::Double());
     SetFlag(kUseGVN);
     SetGVNFlag(kChangesNewSpacePromotion);
   }
 
@@ skipping 2109 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_