Version 3.3.2....

src/x64/lithium-x64.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 84 matching lines @@
   V(FunctionLiteral)                            \
   V(Gap)                                        \
   V(GetCachedArrayIndex)                        \
   V(GlobalObject)                               \
   V(GlobalReceiver)                             \
   V(Goto)                                       \
   V(HasCachedArrayIndex)                        \
   V(HasCachedArrayIndexAndBranch)               \
   V(HasInstanceType)                            \
   V(HasInstanceTypeAndBranch)                   \
+  V(In)                                         \
   V(InstanceOf)                                 \
   V(InstanceOfAndBranch)                        \
   V(InstanceOfKnownGlobal)                      \
   V(Integer32ToDouble)                          \
   V(InvokeFunction)                             \
   V(IsNull)                                     \
   V(IsNullAndBranch)                            \
   V(IsObject)                                   \
   V(IsObjectAndBranch)                          \
   V(IsSmi)                                      \
@@ skipping 708 matching lines @@
     inputs_[1] = right;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(CmpTAndBranch, "cmp-t-and-branch")
   DECLARE_HYDROGEN_ACCESSOR(Compare)
 
   Token::Value op() const { return hydrogen()->token(); }
 };
 
 
+class LIn: public LTemplateInstruction<1, 2, 0> {
+ public:
+  LIn(LOperand* key, LOperand* object) {
+    inputs_[0] = key;
+    inputs_[1] = object;
+  }
+
+  LOperand* key() { return inputs_[0]; }
+  LOperand* object() { return inputs_[1]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(In, "in")
+};
+
+
 class LInstanceOf: public LTemplateInstruction<1, 2, 0> {
  public:
   LInstanceOf(LOperand* left, LOperand* right) {
     inputs_[0] = left;
     inputs_[1] = right;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(InstanceOf, "instance-of")
 };
 
@@ skipping 1347 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_