Add GetProperty/GetElement to JSReceiver and use it where possible

src/contexts.cc

 // Copyright 2011 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/contexts.h"
 
 #include "src/ast/scopeinfo.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
@@ skipping 146 matching lines @@
  */
 static Maybe<bool> UnscopableLookup(LookupIterator* it) {
   Isolate* isolate = it->isolate();
 
   Maybe<bool> found = JSReceiver::HasProperty(it);
   if (!found.IsJust() || !found.FromJust()) return found;
 
   Handle<Object> unscopables;
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
       isolate, unscopables,
-      Object::GetProperty(it->GetReceiver(),
-                          isolate->factory()->unscopables_symbol()),
+      JSReceiver::GetProperty(Handle<JSReceiver>::cast(it->GetReceiver()),
+                              isolate->factory()->unscopables_symbol()),
       Nothing<bool>());
   if (!unscopables->IsJSReceiver()) return Just(true);
   Handle<Object> blacklist;
-  ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, blacklist,
-                                   Object::GetProperty(unscopables, it->name()),
-                                   Nothing<bool>());
+  ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+      isolate, blacklist,
+      JSReceiver::GetProperty(Handle<JSReceiver>::cast(unscopables),
+                              it->name()),
+      Nothing<bool>());
   return Just(!blacklist->BooleanValue());
 }
 
 static void GetAttributesAndBindingFlags(VariableMode mode,
                                          InitializationFlag init_flag,
                                          PropertyAttributes* attributes,
                                          BindingFlags* binding_flags) {
   switch (mode) {
     case VAR:
       *attributes = NONE;
@@ skipping 395 matching lines @@
 
   int previous_value = errors_thrown()->value();
   set_errors_thrown(Smi::FromInt(previous_value + 1));
 }
 
 
 int Context::GetErrorsThrown() { return errors_thrown()->value(); }
 
 }  // namespace internal
 }  // namespace v8