Fix representation of HLoadRoot.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 695c629a7049dc051fdc33a06751ef7ecadce622..64decbf13ba6db2f7de73aa15454efbf74411a20 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -2716,6 +2716,7 @@ class HLoadRoot FINAL : public HTemplateInstruction<0> {
     // TODO(bmeurer): We'll need kDependsOnRoots once we add the
     // corresponding HStoreRoot instruction.
     SetDependsOnFlag(kCalls);
+    set_representation(Representation::Tagged());
   }
 
   virtual bool IsDeletable() const OVERRIDE { return true; }
@@ -6376,6 +6377,7 @@ class HLoadNamedField FINAL : public HTemplateInstruction<2> {
       // object must be external in case of external memory access
       return Representation::External();
     }
+    if (index == 1) return Representation::None();
     return Representation::Tagged();
   }
   virtual Range* InferRange(Zone* zone) OVERRIDE;