Reland of [turbofan] Restore basic write barrier elimination.

test/cctest/test-unboxed-doubles.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 <stdlib.h>
 #include <utility>
 
 #include "src/v8.h"
 
 #include "src/compilation-cache.h"
@@ skipping 1486 matching lines @@
   CHECK(!MarkCompactCollector::IsOnEvacuationCandidate(*obj_value));
 
   if (check_tagged_value) {
     FieldIndex tagged_field_index =
         FieldIndex::ForDescriptor(*new_map, tagged_descriptor);
     CHECK_EQ(*obj_value, obj->RawFastPropertyAt(tagged_field_index));
   }
   CHECK_EQ(boom_value, obj->RawFastDoublePropertyAt(double_field_index));
 }
 
-
-enum WriteBarrierKind { OLD_TO_OLD_WRITE_BARRIER, OLD_TO_NEW_WRITE_BARRIER };
+enum OldToWriteBarrierKind {
+  OLD_TO_OLD_WRITE_BARRIER,
+  OLD_TO_NEW_WRITE_BARRIER
+};
 static void TestWriteBarrierObjectShiftFieldsRight(
-    WriteBarrierKind write_barrier_kind) {
+    OldToWriteBarrierKind write_barrier_kind) {
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   v8::HandleScope scope(CcTest::isolate());
 
   Handle<FieldType> any_type = FieldType::Any(isolate);
 
   CompileRun("function func() { return 1; }");
 
   Handle<JSObject> func = GetObject("func");
 
@@ skipping 31 matching lines @@
 
 // TODO(ishell): add respective tests for property kind reconfiguring from
 // accessor field to double, once accessor fields are supported by
 // Map::ReconfigureProperty().
 
 
 // TODO(ishell): add respective tests for fast property removal case once
 // Map::ReconfigureProperty() supports that.
 
 #endif