Introduce global contexts to represent lexical global scope(s).

src/contexts.cc

 // Copyright 2011 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 295 matching lines @@
 
 
 #ifdef DEBUG
 bool Context::IsBootstrappingOrValidParentContext(
     Object* object, Context* child) {
   // During bootstrapping we allow all objects to pass as
   // contexts. This is necessary to fix circular dependencies.
   if (Isolate::Current()->bootstrapper()->IsActive()) return true;
   if (!object->IsContext()) return false;
   Context* context = Context::cast(object);
-  return context->IsNativeContext() || context->IsModuleContext() ||
-         !child->IsModuleContext();
+  return context->IsNativeContext() || context->IsGlobalContext() ||
+         context->IsModuleContext() || !child->IsModuleContext();
 }
 
 
 bool Context::IsBootstrappingOrGlobalObject(Object* object) {
   // During bootstrapping we allow all objects to pass as global
   // objects. This is necessary to fix circular dependencies.
   Isolate* isolate = Isolate::Current();
   return isolate->heap()->gc_state() != Heap::NOT_IN_GC ||
       isolate->bootstrapper()->IsActive() ||
       object->IsGlobalObject();
 }
 #endif
 
 } }  // namespace v8::internal