Add script context with context-allocated "const this"

test/unittests/compiler/js-type-feedback-unittest.cc

 // Copyright 2015 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/compiler.h"
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/js-type-feedback.h"
@@ skipping 65 matching lines @@
 
   Node* ReturnLoadNamedFromGlobal(
       const char* string, Node* effect, Node* control,
       JSTypeFeedbackSpecializer::DeoptimizationMode mode) {
     ResolvedFeedbackSlot feedback;
     Node* global = Parameter(Type::GlobalObject());
     Node* vector = UndefinedConstant();
     Node* context = UndefinedConstant();
 
     Unique<Name> name = Unique<Name>::CreateUninitialized(
-        isolate()->factory()->NewStringFromAsciiChecked(string));
+        isolate()->factory()->InternalizeUtf8String(string));
     const Operator* op = javascript()->LoadNamed(name, feedback);
     Node* load = graph()->NewNode(op, global, vector, context);
     if (mode == JSTypeFeedbackSpecializer::kDeoptimizationEnabled) {
       for (int i = 0; i < OperatorProperties::GetFrameStateInputCount(op);
            i++) {
         load->AppendInput(zone(), EmptyFrameState());
       }
     }
     load->AppendInput(zone(), effect);
     load->AppendInput(zone(), control);
@@ skipping 238 matching lines @@
               IsReturn(load_field_match, load_field_match, graph()->start()));
   EXPECT_THAT(graph()->end(), IsEnd(ret));
 
   EXPECT_FALSE(dependencies()->IsEmpty());
   dependencies()->Rollback();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8