Alias HStoreNamedField::observed_input_representation to its required input representation.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 257233b0f6a87e676b023fe9793e9f310fde83c6..7be156f69f44bfd554391d4f5fa80b230dcbd8db 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -5911,6 +5911,11 @@ class HStoreNamedField: public HTemplateInstruction<3> {
     }
     return Representation::Tagged();
   }
+
+  virtual Representation observed_input_representation(int index) {
+    return RequiredInputRepresentation(index);
+  }
+
   virtual void HandleSideEffectDominator(GVNFlag side_effect,
                                          HValue* dominator) {
     ASSERT(side_effect == kChangesNewSpacePromotion);