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..20fe5cfaaa626dcb9ffdc238857a0b09ec3e7374 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1766,6 +1766,12 @@ LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoCheckSmiOrInt32(HCheckSmiOrInt32* instr) {
+  LOperand* value = UseRegisterAtStart(instr->value());
+  return AssignEnvironment(new(zone()) LCheckSmi(value));
+}
+
+
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckFunction(value));