Introduce NonJSProxyHolder returning Handle<JSObject> and return Handle<JSReceiver> for GetHolder

src/lookup.h

 // 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.
 
 #ifndef V8_LOOKUP_H_
 #define V8_LOOKUP_H_
 
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/objects.h"
@@ skipping 75 matching lines @@
 
   bool IsFound() const { return state_ != NOT_FOUND; }
   void Next();
 
   Heap* heap() const { return isolate_->heap(); }
   Factory* factory() const { return isolate_->factory(); }
   Handle<Object> GetReceiver() const {
     return Handle<Object>::cast(maybe_receiver_.ToHandleChecked());
   }
   Handle<Map> holder_map() const { return holder_map_; }
-  Handle<JSObject> GetHolder() const {
-    ASSERT(IsFound() && state_ != JSPROXY);
-    return Handle<JSObject>::cast(maybe_holder_.ToHandleChecked());
+  template <class T>
+  Handle<T> GetHolder() const {
+    ASSERT(IsFound());
+    return Handle<T>::cast(maybe_holder_.ToHandleChecked());
   }
   Handle<JSReceiver> GetRoot() const;
   bool HolderIsReceiver() const;
 
   /* Dynamically reduce the trapped types. */
   void skip_interceptor() {
     configuration_ = static_cast<Configuration>(
         configuration_ & ~CHECK_INTERCEPTOR);
   }
   void skip_access_check() {
@@ skipping 25 matching lines @@
     ASSERT(has_property_);
     ASSERT_EQ(DESCRIPTOR, property_encoding_);
     return number_;
   }
   Handle<Object> GetAccessors() const;
   Handle<Object> GetDataValue() const;
   void WriteDataValue(Handle<Object> value);
 
   void InternalizeName();
 
-  /* JSPROXY */
-  Handle<JSProxy> GetJSProxy() const {
-    return Handle<JSProxy>::cast(maybe_holder_.ToHandleChecked());
-  }
-
  private:
   Handle<Map> GetReceiverMap() const;
 
   MUST_USE_RESULT bool NextHolder();
   State LookupInHolder();
   Handle<Object> FetchValue() const;
 
   bool IsBootstrapping() const;
 
   // Methods that fetch data from the holder ensure they always have a holder.
@@ skipping 28 matching lines @@
   MaybeHandle<Object> maybe_receiver_;
   MaybeHandle<JSReceiver> maybe_holder_;
 
   int number_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOOKUP_H_