[turbofan] Remove unused BuildLoadGlobalProxy from AstGraphBuilder.

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/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/linkage.h"
@@ skipping 3639 matching lines @@
 
 
 Node* AstGraphBuilder::BuildLoadNativeContextField(int index) {
   Node* global = BuildLoadGlobalObject();
   Node* native_context =
       BuildLoadObjectField(global, JSGlobalObject::kNativeContextOffset);
   return NewNode(javascript()->LoadContext(0, index, true), native_context);
 }
 
 
-Node* AstGraphBuilder::BuildLoadGlobalProxy() {
-  Node* global = BuildLoadGlobalObject();
-  Node* proxy =
-      BuildLoadObjectField(global, JSGlobalObject::kGlobalProxyOffset);
-  return proxy;
-}
-
-
 Node* AstGraphBuilder::BuildLoadFeedbackVector() {
   if (!feedback_vector_.is_set()) {
     Node* closure = GetFunctionClosure();
     Node* shared = BuildLoadImmutableObjectField(
         closure, JSFunction::kSharedFunctionInfoOffset);
     Node* vector = BuildLoadImmutableObjectField(
         shared, SharedFunctionInfo::kFeedbackVectorOffset);
     feedback_vector_.set(vector);
   }
   return feedback_vector_.get();
@@ skipping 647 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