Internalize if not yet internalized

src/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/hydrogen.h"
 
 #include <algorithm>
 
 #include "src/v8.h"
 
@@ skipping 7120 matching lines @@
 HValue* HOptimizedGraphBuilder::HandleKeyedElementAccess(
     HValue* obj, HValue* key, HValue* val, Expression* expr,
     BailoutId return_id, PropertyAccessType access_type,
     bool* has_side_effects) {
   if (key->ActualValue()->IsConstant()) {
     Handle<Object> constant =
         HConstant::cast(key->ActualValue())->handle(isolate());
     uint32_t array_index;
     if (constant->IsString() &&
         !Handle<String>::cast(constant)->AsArrayIndex(&array_index)) {
+      if (!constant->IsUniqueName()) {
+        constant = isolate()->factory()->InternalizeString(
+            Handle<String>::cast(constant));
+      }
       HInstruction* instr =
           BuildNamedAccess(access_type, expr->id(), return_id, expr, obj,
                            Handle<String>::cast(constant), val, false);
       if (instr == NULL || instr->IsLinked()) {
         *has_side_effects = false;
       } else {
         AddInstruction(instr);
         *has_side_effects = instr->HasObservableSideEffects();
       }
       return instr;
@@ skipping 5368 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal