Never hchange nan-hole to hole or hole to nan-hole.

src/hydrogen-mark-deoptimize.h

Index: src/hydrogen-mark-deoptimize.h
diff --git a/src/hydrogen-mark-deoptimize.h b/src/hydrogen-mark-deoptimize.h
index 0aa2c2c754069e4cf658429707a02ffe8fe4fa92..30f35b3dec59046c0893e55981b064fe15c37726 100644
--- a/src/hydrogen-mark-deoptimize.h
+++ b/src/hydrogen-mark-deoptimize.h
@@ -58,6 +58,18 @@ class HMarkDeoptimizeOnUndefinedPhase : public HPhase {
 };
 
 
+class HComputeChangeUndefinedToNaN : public HPhase {
+ public:
+  explicit HComputeChangeUndefinedToNaN(HGraph* graph)
+      : HPhase("H_Compute change undefined to nan", graph) {}
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HComputeChangeUndefinedToNaN);
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_MARK_DEOPTIMIZE_H_