Don't MISS if you read the hole from certain FastHoley arrays.

src/x64/lithium-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sstream>
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
@@ skipping 2199 matching lines @@
   } else {
     DCHECK(
         (instr->representation().IsInteger32() &&
          !(IsDoubleOrFloatElementsKind(elements_kind))) ||
         (instr->representation().IsDouble() &&
          (IsDoubleOrFloatElementsKind(elements_kind))));
     LOperand* backing_store = UseRegister(instr->elements());
     result = DefineAsRegister(new(zone()) LLoadKeyed(backing_store, key));
   }
 
-  if ((instr->is_external() || instr->is_fixed_typed_array()) ?
-      // see LCodeGen::DoLoadKeyedExternalArray
-      ((elements_kind == EXTERNAL_UINT32_ELEMENTS ||
-        elements_kind == UINT32_ELEMENTS) &&
-       !instr->CheckFlag(HInstruction::kUint32)) :
-      // see LCodeGen::DoLoadKeyedFixedDoubleArray and
-      // LCodeGen::DoLoadKeyedFixedArray
-      instr->RequiresHoleCheck()) {
+  bool needs_environment;
+  if (instr->is_external() || instr->is_fixed_typed_array()) {
+    // see LCodeGen::DoLoadKeyedExternalArray
+    needs_environment = (elements_kind == EXTERNAL_UINT32_ELEMENTS ||
+                         elements_kind == UINT32_ELEMENTS) &&
+                        !instr->CheckFlag(HInstruction::kUint32);
+  } else {
+    // see LCodeGen::DoLoadKeyedFixedDoubleArray and
+    // LCodeGen::DoLoadKeyedFixedArray
+    needs_environment =
+        instr->RequiresHoleCheck() ||
+        (instr->hole_mode() == CONVERT_HOLE_TO_UNDEFINED && info()->IsStub());
+  }
+
+  if (needs_environment) {
     result = AssignEnvironment(result);
   }
   return result;
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), rsi);
   LOperand* object =
       UseFixed(instr->object(), LoadDescriptor::ReceiverRegister());
@@ skipping 448 matching lines @@
   LOperand* function = UseRegisterAtStart(instr->function());
   LAllocateBlockContext* result =
       new(zone()) LAllocateBlockContext(context, function);
   return MarkAsCall(DefineFixed(result, rsi), instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64