Eliminate intentional conversion from Smi to Int32 in HMul

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 815a6c69f5d7ff66adb2384c66695f76d4bbef19..8a80f79f171588570793298ab2311d6051df8e76 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -802,6 +802,8 @@ class HValue: public ZoneObject {
 
   // Returns true if the flag specified is set for all uses, false otherwise.
   bool CheckUsesForFlag(Flag f);
+  // Same as before and the first one without the flag is returned in value.
+  bool CheckUsesForFlag(Flag f, HValue** value);
   // Returns true if the flag specified is set for all uses, and this set
   // of uses is non-empty.
   bool HasAtLeastOneUseWithFlagAndNoneWithout(Flag f);
@@ -1530,7 +1532,10 @@ class HChange: public HUnaryOperation {
     set_representation(to);
     SetFlag(kUseGVN);
     if (allow_undefined_as_nan) SetFlag(kAllowUndefinedAsNaN);
-    if (is_truncating_to_smi) SetFlag(kTruncatingToSmi);
+    if (is_truncating_to_smi) {
+      SetFlag(kTruncatingToSmi);
+      SetFlag(kTruncatingToInt32);
+    }
     if (is_truncating_to_int32) SetFlag(kTruncatingToInt32);
     if (value->representation().IsSmi() || value->type().IsSmi()) {
       set_type(HType::Smi());
@@ -4434,7 +4439,6 @@ class HMul: public HArithmeticBinaryOperation {
   virtual void UpdateRepresentation(Representation new_rep,
                                     HInferRepresentationPhase* h_infer,
                                     const char* reason) {
-    if (new_rep.IsSmi()) new_rep = Representation::Integer32();
     HArithmeticBinaryOperation::UpdateRepresentation(new_rep, h_infer, reason);
   }
 
@@ -4646,6 +4650,7 @@ class HBitwise: public HBitwiseBinaryOperation {
           right->representation().IsSmi() &&
           HConstant::cast(right)->Integer32Value() >= 0))) {
       SetFlag(kTruncatingToSmi);
+      SetFlag(kTruncatingToInt32);
     // BIT_OR with a smi-range negative value will always set the entire
     // sign-extension of the smi-sign.
     } else if (op == Token::BIT_OR &&
@@ -4656,6 +4661,7 @@ class HBitwise: public HBitwiseBinaryOperation {
           right->representation().IsSmi() &&
           HConstant::cast(right)->Integer32Value() < 0))) {
       SetFlag(kTruncatingToSmi);
+      SetFlag(kTruncatingToInt32);
     }
   }