Set kTruncatingToSmi for HChange only when To rep is Smi

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 81ecb890bf9c22551202bb6b2e51d19c0abd10ac..33cf2f72e6251976ecacf08ac1667545f9d6ae04 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -1263,6 +1263,7 @@ class HInstruction : public HValue {
     position_.set_operand_position(index, pos);
   }
 
+  bool CanTruncateToSmi() const { return CheckFlag(kTruncatingToSmi); }
   bool CanTruncateToInt32() const { return CheckFlag(kTruncatingToInt32); }
 
   virtual LInstruction* CompileToLithium(LChunkBuilder* builder) = 0;
@@ -1733,7 +1734,7 @@ class HChange V8_FINAL : public HUnaryOperation {
     set_representation(to);
     SetFlag(kUseGVN);
     SetFlag(kCanOverflow);
-    if (is_truncating_to_smi) {
+    if (is_truncating_to_smi && to.IsSmi()) {
       SetFlag(kTruncatingToSmi);
       SetFlag(kTruncatingToInt32);
     }