Explicitly disallow stores to JSObjectAccessors (for now).

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5424 matching lines @@
     map->LookupDescriptor(*holder_, *name_, &lookup_);
     if (lookup_.IsFound()) return LoadResult(map);
   }
   lookup_.NotFound();
   return true;
 }
 
 
 bool HOptimizedGraphBuilder::PropertyAccessInfo::CanAccessMonomorphic() {
   if (!CanInlinePropertyAccess(type_)) return false;
-  if (IsJSObjectFieldAccessor()) {
-    // We should never have gathered typefeedback for JSObjectFieldAccessor
-    // stores.
-    ASSERT(IsLoad());
-    return true;
-  }
+  if (IsJSObjectFieldAccessor()) return IsLoad();
   if (!LookupDescriptor()) return false;
   if (lookup_.IsFound()) {
     if (IsLoad()) return true;
     return !lookup_.IsReadOnly() && lookup_.IsCacheable();
   }
   if (!LookupInPrototypes()) return false;
   if (IsLoad()) return true;
 
   if (lookup_.IsPropertyCallbacks()) return true;
   Handle<Map> map = this->map();
@@ skipping 5766 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal