Allocate block-scoped global bindings to global context.

src/objects.h

 // Copyright 2012 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 6180 matching lines @@
 // Common super class for JavaScript global objects and the special
 // builtins global objects.
 class GlobalObject: public JSObject {
  public:
   // [builtins]: the object holding the runtime routines written in JS.
   DECL_ACCESSORS(builtins, JSBuiltinsObject)
 
   // [native context]: the natives corresponding to this global object.
   DECL_ACCESSORS(native_context, Context)
 
+  // [global context]: the most recent (i.e. innermost) global context.
+  DECL_ACCESSORS(global_context, Context)
+
   // [global receiver]: the global receiver object of the context
   DECL_ACCESSORS(global_receiver, JSObject)
 
   // Retrieve the property cell used to store a property.
   JSGlobalPropertyCell* GetPropertyCell(LookupResult* result);
 
   // This is like GetProperty, but is used when you know the lookup won't fail
   // by throwing an exception.  This is for the debug and builtins global
   // objects, where it is known which properties can be expected to be present
   // on the object.
   Object* GetPropertyNoExceptionThrown(String* key) {
     Object* answer = GetProperty(key)->ToObjectUnchecked();
     return answer;
   }
 
   // Ensure that the global object has a cell for the given property name.
   static Handle<JSGlobalPropertyCell> EnsurePropertyCell(
       Handle<GlobalObject> global,
       Handle<String> name);
   // TODO(kmillikin): This function can be eliminated once the stub cache is
   // full handlified (and the static helper can be written directly).
   MUST_USE_RESULT MaybeObject* EnsurePropertyCell(String* name);
 
   // Casting.
   static inline GlobalObject* cast(Object* obj);
 
   // Layout description.
   static const int kBuiltinsOffset = JSObject::kHeaderSize;
   static const int kNativeContextOffset = kBuiltinsOffset + kPointerSize;
-  static const int kGlobalReceiverOffset = kNativeContextOffset + kPointerSize;
+  static const int kGlobalContextOffset = kNativeContextOffset + kPointerSize;
+  static const int kGlobalReceiverOffset = kGlobalContextOffset + kPointerSize;
   static const int kHeaderSize = kGlobalReceiverOffset + kPointerSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject);
 };
 
 
 // JavaScript global object.
 class JSGlobalObject: public GlobalObject {
  public:
@@ skipping 2691 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_