Allow lazy compilation (and thus optimisation) of functions inside eval.

src/contexts.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 333 matching lines @@
 
   // The builtins object.
   JSBuiltinsObject* builtins();
 
   // Get the innermost global context by traversing the context chain.
   Context* global_context();
 
   // Compute the native context by traversing the context chain.
   Context* native_context();
 
-  // Predicates for context types.  IsNativeContext is defined on Object
+  // Predicates for context types.  IsNativeContext is also defined on Object
   // because we frequently have to know if arbitrary objects are natives
   // contexts.
+  bool IsNativeContext() {
+    Map* map = this->map();
+    return map == map->GetHeap()->native_context_map();
+  }
   bool IsFunctionContext() {
     Map* map = this->map();
     return map == map->GetHeap()->function_context_map();
   }
   bool IsCatchContext() {
     Map* map = this->map();
     return map == map->GetHeap()->catch_context_map();
   }
   bool IsWithContext() {
     Map* map = this->map();
@@ skipping 87 matching lines @@
   static bool IsBootstrappingOrGlobalObject(Object* object);
 #endif
 
   STATIC_CHECK(kHeaderSize == Internals::kContextHeaderSize);
   STATIC_CHECK(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CONTEXTS_H_