Fix uint32-to-smi conversion in Lithium

src/x64/lithium-x64.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 163 matching lines @@
   V(SubI)                                       \
   V(TaggedToI)                                  \
   V(ThisFunction)                               \
   V(Throw)                                      \
   V(ToFastProperties)                           \
   V(TransitionElementsKind)                     \
   V(TrapAllocationMemento)                      \
   V(Typeof)                                     \
   V(TypeofIsAndBranch)                          \
   V(Uint32ToDouble)                             \
+  V(Uint32ToSmi)                                \
   V(UnknownOSRValue)                            \
   V(ValueOf)                                    \
   V(WrapReceiver)
 
 
 #define DECLARE_CONCRETE_INSTRUCTION(type, mnemonic)                        \
   virtual Opcode opcode() const V8_FINAL V8_OVERRIDE {                      \
     return LInstruction::k##type;                                           \
   }                                                                         \
   virtual void CompileToNative(LCodeGen* generator) V8_FINAL V8_OVERRIDE;   \
@@ skipping 1742 matching lines @@
     temps_[0] = temp;
   }
 
   LOperand* value() { return inputs_[0]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(Uint32ToDouble, "uint32-to-double")
 };
 
 
+class LUint32ToSmi V8_FINAL : public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LUint32ToSmi(LOperand* value) {
+    inputs_[0] = value;
+  }
+
+  LOperand* value() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(Uint32ToSmi, "uint32-to-smi")
+  DECLARE_HYDROGEN_ACCESSOR(Change)
+};
+
+
 class LNumberTagI V8_FINAL : public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LNumberTagI(LOperand* value) {
     inputs_[0] = value;
   }
 
   LOperand* value() { return inputs_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(NumberTagI, "number-tag-i")
 };
@@ skipping 741 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_