Handle holes in smi-untag from LoadKeyed requiring hole handling.

src/x64/lithium-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1807 matching lines @@
   if (from.IsTagged()) {
     if (to.IsDouble()) {
       info()->MarkAsDeferredCalling();
       LOperand* value = UseRegister(instr->value());
       LNumberUntagD* res = new(zone()) LNumberUntagD(value);
       return AssignEnvironment(DefineAsRegister(res));
     } else {
       ASSERT(to.IsInteger32());
       LOperand* value = UseRegister(instr->value());
       if (instr->value()->type().IsSmi()) {
-        return DefineSameAsFirst(new(zone()) LSmiUntag(value, false));
+        LInstruction* result =
+            DefineSameAsFirst(new(zone()) LSmiUntag(value, false));
+        if (instr->value()->IsLoadKeyed()) {
+          HLoadKeyed* load_keyed = HLoadKeyed::cast(instr->value());
+          if (load_keyed->UsesMustHandleHole() &&
+              load_keyed->hole_mode() == NEVER_RETURN_HOLE) {
+            return AssignEnvironment(result);
+          }
+        }
+        return result;
       } else {
         bool truncating = instr->CanTruncateToInt32();
         LOperand* xmm_temp = truncating ? NULL : FixedTemp(xmm1);
         LTaggedToI* res = new(zone()) LTaggedToI(value, xmm_temp);
         return AssignEnvironment(DefineSameAsFirst(res));
       }
     }
   } else if (from.IsDouble()) {
     if (to.IsTagged()) {
       info()->MarkAsDeferredCalling();
@@ skipping 710 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64