Don't take UnkownOSRValues into account when infering Phi's representation.

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 2243 matching lines @@
         is_convertible_to_integer_(true) {
     for (int i = 0; i < Representation::kNumRepresentations; i++) {
       non_phi_uses_[i] = 0;
       indirect_uses_[i] = 0;
     }
     ASSERT(merged_index >= 0);
     set_representation(Representation::Tagged());
     SetFlag(kFlexibleRepresentation);
   }
 
-  virtual Representation InferredRepresentation() {
-    bool double_occurred = false;
-    bool int32_occurred = false;
-    for (int i = 0; i < OperandCount(); ++i) {
-      HValue* value = OperandAt(i);
-      if (value->representation().IsDouble()) double_occurred = true;
-      if (value->representation().IsInteger32()) int32_occurred = true;
-      if (value->representation().IsTagged()) return Representation::Tagged();
-    }
-
-    if (double_occurred) return Representation::Double();
-    if (int32_occurred) return Representation::Integer32();
-    return Representation::None();
-  }
+  virtual Representation InferredRepresentation();
 
   virtual Range* InferRange(Zone* zone);
   virtual Representation RequiredInputRepresentation(int index) {
     return representation();
   }
   virtual HType CalculateInferredType();
   virtual int OperandCount() { return inputs_.length(); }
   virtual HValue* OperandAt(int index) { return inputs_[index]; }
   HValue* GetRedundantReplacement();
   void AddInput(HValue* value);
@@ skipping 2532 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(LoadFieldByIndex);
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_