[turbofan] Restore basic write barrier elimination.

src/compiler/access-builder.h

Index: src/compiler/access-builder.h
diff --git a/src/compiler/access-builder.h b/src/compiler/access-builder.h
index 226456714dbbca91a64f9d53376a4988defd72a5..b36277e1b69ec1a6c570f32f33571c998a94e1a7 100644
--- a/src/compiler/access-builder.h
+++ b/src/compiler/access-builder.h
@@ -142,12 +142,6 @@ class AccessBuilder final : public AllStatic {
   static ElementAccess ForTypedArrayElement(ExternalArrayType type,
                                             bool is_external);
 
-  // ===========================================================================
-  // Access to global per-isolate variables (based on external reference).
-
-  // Provides access to the backing store of a StatsCounter.
-  static FieldAccess ForStatsCounter();
-
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessBuilder);
 };