[crankshaft] Remove dead Variable hole-checking code

src/crankshaft/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 "src/crankshaft/x64/lithium-x64.h"
 
 #include <sstream>
 
 #if V8_TARGET_ARCH_X64
 
@@ skipping 1943 matching lines @@
     return DefineAsRegister(new(zone()) LConstantT);
   } else {
     UNREACHABLE();
     return NULL;
   }
 }
 
 
 LInstruction* LChunkBuilder::DoLoadContextSlot(HLoadContextSlot* instr) {
   LOperand* context = UseRegisterAtStart(instr->value());
-  LInstruction* result =
-      DefineAsRegister(new(zone()) LLoadContextSlot(context));
-  if (instr->RequiresHoleCheck() && instr->DeoptimizesOnHole()) {
-    result = AssignEnvironment(result);
-  }
-  return result;
+  return DefineAsRegister(new (zone()) LLoadContextSlot(context));
 }
 
 
 LInstruction* LChunkBuilder::DoStoreContextSlot(HStoreContextSlot* instr) {
   LOperand* context;
   LOperand* value;
   LOperand* temp;
   context = UseRegister(instr->context());
   if (instr->NeedsWriteBarrier()) {
     value = UseTempRegister(instr->value());
     temp = TempRegister();
   } else {
     value = UseRegister(instr->value());
     temp = NULL;
   }
-  LInstruction* result = new(zone()) LStoreContextSlot(context, value, temp);
-  if (instr->RequiresHoleCheck() && instr->DeoptimizesOnHole()) {
-    result = AssignEnvironment(result);
-  }
-  return result;
+  return new (zone()) LStoreContextSlot(context, value, temp);
 }
 
 
 LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
   // Use the special mov rax, moffs64 encoding for external
   // memory accesses with 64-bit word-sized values.
   if (instr->access().IsExternalMemory() &&
       instr->access().offset() == 0 &&
       (instr->access().representation().IsSmi() ||
        instr->access().representation().IsTagged() ||
@@ skipping 466 matching lines @@
   LOperand* index = UseTempRegister(instr->index());
   LLoadFieldByIndex* load = new(zone()) LLoadFieldByIndex(object, index);
   LInstruction* result = DefineSameAsFirst(load);
   return AssignPointerMap(result);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64