[turbofan] Remove obsolete BuildLoadBuiltinsObject.

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index 12e121b5069474590509ccf22eea2773f1715fbd..22d9e7ab5efd9850e233f17f79bb4e007f67edf9 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -3737,14 +3737,6 @@ Node* AstGraphBuilder::BuildLoadImmutableObjectField(Node* object, int offset) {
 }
 
 
-Node* AstGraphBuilder::BuildLoadBuiltinsObject() {
-  Node* global = BuildLoadGlobalObject();
-  Node* builtins =
-      BuildLoadObjectField(global, JSGlobalObject::kBuiltinsOffset);
-  return builtins;
-}
-
-
 Node* AstGraphBuilder::BuildLoadGlobalObject() {
   const Operator* load_op =
       javascript()->LoadContext(0, Context::GLOBAL_OBJECT_INDEX, true);