use a hash table for the function cache as blink is leaking functiontemplates

src/api-natives.h

 // Copyright 2015 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.
 
 #ifndef V8_API_NATIVES_H_
 #define V8_API_NATIVES_H_
 
 #include "src/handles.h"
 
 namespace v8 {
 namespace internal {
 
 class ApiNatives {
  public:
+  static const int kInitialFunctionCacheSize = 256;
+
   MUST_USE_RESULT static MaybeHandle<JSFunction> InstantiateFunction(
       Handle<FunctionTemplateInfo> data);
 
   MUST_USE_RESULT static MaybeHandle<JSObject> InstantiateObject(
       Handle<ObjectTemplateInfo> data);
 
   MUST_USE_RESULT static MaybeHandle<FunctionTemplateInfo> ConfigureInstance(
       Isolate* isolate, Handle<FunctionTemplateInfo> instance,
       Handle<JSObject> data);
 
@@ skipping 19 matching lines @@
                                   PropertyAttributes attributes);
 
   static void AddNativeDataProperty(Isolate* isolate, Handle<TemplateInfo> info,
                                     Handle<AccessorInfo> property);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif