Separated smi check from HBoundsCheck.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index e35a381faacd932d223a4a64d1d45a317e491007..4d8e602256fb7921a16e3ef6bdce4448334ed23c 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1766,6 +1766,16 @@ LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoCheckSmiOrInt32(HCheckSmiOrInt32* instr) {
+  if (instr->representation().IsTagged() && !instr->type().IsSmi()) {
+    LOperand* value = UseRegisterAtStart(instr->value());
+    return AssignEnvironment(new(zone()) LCheckSmi(value));
+  } else {
+    return NULL;
+  }
+}
+
+
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckFunction(value));