Restore PushStackTraceAndDie for the case where we lookup starting with null

src/lookup.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/bootstrapper.h"
 #include "src/deoptimizer.h"
 #include "src/lookup.h"
 #include "src/lookup-inl.h"
@@ skipping 45 matching lines @@
   holder_ = initial_holder_;
   holder_map_ = handle(holder_->map(), isolate_);
   Next();
 }
 
 
 Handle<JSReceiver> LookupIterator::GetRoot(Handle<Object> receiver,
                                            Isolate* isolate) {
   if (receiver->IsJSReceiver()) return Handle<JSReceiver>::cast(receiver);
   auto root = handle(receiver->GetRootMap(isolate)->prototype(), isolate);
-  CHECK(!root->IsNull());
+  if (root->IsNull()) {
+    unsigned int magic = 0xbbbbbbbb;
+    isolate->PushStackTraceAndDie(magic, *receiver, NULL, magic);
+  }
   return Handle<JSReceiver>::cast(root);
 }
 
 
 Handle<Map> LookupIterator::GetReceiverMap() const {
   if (receiver_->IsNumber()) return isolate_->factory()->heap_number_map();
   return handle(Handle<HeapObject>::cast(receiver_)->map(), isolate_);
 }
 
 
@@ skipping 309 matching lines @@
       // Fall through.
       case InterceptorState::kSkipNonMasking:
         return true;
       case InterceptorState::kProcessNonMasking:
         return false;
     }
   }
   return interceptor_state_ == InterceptorState::kProcessNonMasking;
 }
 } }  // namespace v8::internal