Fixed issue in StoreNamedField codegen where integer32 constants were not converted to a smi.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 3943 matching lines @@
 
   Register write_register = object;
   if (!instr->is_in_object()) {
     write_register = ToRegister(instr->temp());
     __ movq(write_register, FieldOperand(object, JSObject::kPropertiesOffset));
   }
 
   if (instr->value()->IsConstantOperand()) {
     LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
     if (IsInteger32Constant(operand_value)) {
-      int const_value = ToInteger32(operand_value);
-      __ movq(FieldOperand(write_register, offset), Immediate(const_value));
+      // In lithium register preparation, we made sure that the constant integer
+      // operand fits into smi range.
+      Smi* smi_value = Smi::FromInt(ToInteger32(operand_value));
+      __ Move(FieldOperand(write_register, offset), smi_value);
+    } else if (operand_value->IsRegister()) {
+      __ movq(FieldOperand(write_register, offset),
+              ToRegister(operand_value));
     } else {
-      if (operand_value->IsRegister()) {
-        __ movq(FieldOperand(write_register, offset),
-                ToRegister(operand_value));
-      } else {
-        Handle<Object> handle_value = ToHandle(operand_value);
-        __ Move(FieldOperand(write_register, offset), handle_value);
-      }
+      Handle<Object> handle_value = ToHandle(operand_value);
+      __ Move(FieldOperand(write_register, offset), handle_value);
     }
   } else {
     __ movq(FieldOperand(write_register, offset), ToRegister(instr->value()));
   }
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     Register value = ToRegister(instr->value());
     Register temp = instr->is_in_object() ? ToRegister(instr->temp()) : object;
     // Update the write barrier for the object for in-object properties.
     __ RecordWriteField(write_register,
@@ skipping 1702 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64