Use Variable::binding_needs_init() to determine hole initialization

src/crankshaft/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
@@ skipping 12144 matching lines @@
     Handle<TypeFeedbackVector> vector(current_feedback_vector(), isolate());
     Add<HDeclareGlobals>(array, flags, vector);
     globals_.Rewind(0);
   }
 }
 
 
 void HOptimizedGraphBuilder::VisitVariableDeclaration(
     VariableDeclaration* declaration) {
   VariableProxy* proxy = declaration->proxy();
-  VariableMode mode = declaration->mode();
   Variable* variable = proxy->var();
-  bool hole_init = mode == LET || mode == CONST;
   switch (variable->location()) {
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
       DCHECK(!variable->binding_needs_init());
       FeedbackVectorSlot slot = proxy->VariableFeedbackSlot();
       DCHECK(!slot.IsInvalid());
       globals_.Add(handle(Smi::FromInt(slot.ToInt()), isolate()), zone());
       globals_.Add(isolate()->factory()->undefined_value(), zone());
       return;
     }
     case VariableLocation::PARAMETER:
     case VariableLocation::LOCAL:
-      if (hole_init) {
+      if (variable->binding_needs_init()) {
         HValue* value = graph()->GetConstantHole();
         environment()->Bind(variable, value);
       }
       break;
     case VariableLocation::CONTEXT:
-      if (hole_init) {
+      if (variable->binding_needs_init()) {
         HValue* value = graph()->GetConstantHole();
         HValue* context = environment()->context();
         HStoreContextSlot* store = Add<HStoreContextSlot>(
             context, variable->index(), HStoreContextSlot::kNoCheck, value);
         if (store->HasObservableSideEffects()) {
           Add<HSimulate>(proxy->id(), REMOVABLE_SIMULATE);
         }
       }
       break;
     case VariableLocation::LOOKUP:
@@ skipping 1223 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8