Allow uint32 value on optimized frames if they are consumed by safe operations.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 00fe92ffb737c0ecc9918021a6d33a5af8503f13..e4dcb2c51b25ef7273beca60e4e1cd2100887596 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -258,6 +258,7 @@ class HGraph: public ZoneObject {
   void InsertRepresentationChanges();
   void MarkDeoptimizeOnUndefined();
   void ComputeMinusZeroChecks();
+  void ComputeSafeUint32Operations();
   bool ProcessArgumentsObject();
   void EliminateRedundantPhis();
   void EliminateUnreachablePhis();
@@ -343,6 +344,13 @@ class HGraph: public ZoneObject {
     return is_recursive_;
   }
 
+  void RecordUint32Instruction(HInstruction* instr) {
+    if (uint32_instructions_ == NULL) {
+      uint32_instructions_ = new(zone()) ZoneList<HInstruction*>(4, zone());
+    }
+    uint32_instructions_->Add(instr, zone());
+  }
+
  private:
   HConstant* GetConstant(SetOncePointer<HConstant>* pointer,
                          Handle<Object> value);
@@ -370,6 +378,7 @@ class HGraph: public ZoneObject {
   ZoneList<HBasicBlock*> blocks_;
   ZoneList<HValue*> values_;
   ZoneList<HPhi*>* phi_list_;
+  ZoneList<HInstruction*>* uint32_instructions_;
   SetOncePointer<HConstant> undefined_constant_;
   SetOncePointer<HConstant> constant_1_;
   SetOncePointer<HConstant> constant_minus1_;