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 1b39f6fd60a9991934972982ad946d24635f99f8..cf77f24aa65e60125f0c4c16ef0bd2a78087cbd5 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -1531,7 +1531,11 @@ 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());
@@ -4431,7 +4435,6 @@ 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);
   }
 
@@ -4643,6 +4646,7 @@ 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 &&
@@ -4653,6 +4657,7 @@ class HBitwise: public HBitwiseBinaryOperation {
           right->representation().IsSmi() &&
           HConstant::cast(right)->Integer32Value() < 0))) {
       SetFlag(kTruncatingToSmi);
+      SetFlag(kTruncatingToInt32);
     }
   }