Revert of [ic] Experiment: disable map-specific handler cache.

test/cctest/test-code-cache.cc

 // Copyright 2016 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/v8.h"
 
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/list.h"
 #include "src/objects.h"
@@ skipping 22 matching lines @@
                    nullptr};  // origin
   Code::Flags flags =
       Code::ComputeFlags(Code::LOAD_IC, kNoExtraICState, kCacheOnReceiver);
   Handle<Code> self_ref;
   return isolate->factory()->NewCode(desc, flags, self_ref);
 }
 
 }  // namespace
 
 TEST(CodeCache) {
-  // TODO(ishell): Experiment: don't cache handlers in map-specific code cache.
-  return;
-
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   Factory* factory = isolate->factory();
   HandleScope handle_scope(isolate);
 
   Handle<Map> map =
       factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize, FAST_ELEMENTS);
 
   // This number should be large enough to cause the code cache to use its
   // hash table storage format.
@@ skipping 24 matching lines @@
   // Check that lookup works not only right after storing.
   for (int i = 0; i < kEntries; i++) {
     Handle<Name> name = names.at(i);
     Handle<Code> code = codes.at(i);
     CHECK_EQ(*code, map->LookupInCodeCache(*name, code->flags()));
   }
 }
 
 }  // namespace internal
 }  // namespace v8