[runtime] Replace global object link with native context link in all contexts.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/ast-graph-builder.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
@@ skipping 3631 matching lines @@
 
 
 Node* AstGraphBuilder::BuildLoadImmutableObjectField(Node* object, int offset) {
   return graph()->NewNode(jsgraph()->machine()->Load(kMachAnyTagged), object,
                           jsgraph()->IntPtrConstant(offset - kHeapObjectTag),
                           graph()->start(), graph()->start());
 }
 
 
 Node* AstGraphBuilder::BuildLoadGlobalObject() {
-  const Operator* load_op =
-      javascript()->LoadContext(0, Context::GLOBAL_OBJECT_INDEX, true);
-  return NewNode(load_op, GetFunctionContext());
+  return BuildLoadNativeContextField(Context::EXTENSION_INDEX);
 }
 
 
 Node* AstGraphBuilder::BuildLoadNativeContextField(int index) {
-  Node* global = BuildLoadGlobalObject();
-  Node* native_context = NewNode(javascript()->LoadNativeContext(), global);
+  const Operator* op =
+      javascript()->LoadContext(0, Context::NATIVE_CONTEXT_INDEX, true);
+  Node* native_context = NewNode(op, current_context());
   return NewNode(javascript()->LoadContext(0, index, true), native_context);
 }
 
 
 Node* AstGraphBuilder::BuildLoadFeedbackVector() {
   if (!feedback_vector_.is_set()) {
     Node* closure = GetFunctionClosure();
     Node* shared = BuildLoadImmutableObjectField(
         closure, JSFunction::kSharedFunctionInfoOffset);
     Node* vector = BuildLoadImmutableObjectField(
@@ skipping 634 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8