Implement `in' for proxies.

src/contexts.h

 // 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 92 matching lines @@
   V(CALL_AS_FUNCTION_DELEGATE_INDEX, JSFunction, call_as_function_delegate) \
   V(CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, JSFunction, \
     call_as_constructor_delegate) \
   V(SCRIPT_FUNCTION_INDEX, JSFunction, script_function) \
   V(OPAQUE_REFERENCE_FUNCTION_INDEX, JSFunction, opaque_reference_function) \
   V(CONTEXT_EXTENSION_FUNCTION_INDEX, JSFunction, context_extension_function) \
   V(OUT_OF_MEMORY_INDEX, Object, out_of_memory) \
   V(MAP_CACHE_INDEX, Object, map_cache) \
   V(CONTEXT_DATA_INDEX, Object, data) \
   V(ALLOW_CODE_GEN_FROM_STRINGS_INDEX, Object, allow_code_gen_from_strings) \
+  V(DERIVED_HAS_TRAP_INDEX, JSFunction, derived_has_trap) \
   V(DERIVED_GET_TRAP_INDEX, JSFunction, derived_get_trap) \
   V(DERIVED_SET_TRAP_INDEX, JSFunction, derived_set_trap)
 
 // JSFunctions are pairs (context, function code), sometimes also called
 // closures. A Context object is used to represent function contexts and
 // dynamically pushed 'with' contexts (or 'scopes' in ECMA-262 speak).
 //
 // At runtime, the contexts build a stack in parallel to the execution
 // stack, with the top-most context being the current context. All contexts
 // have the following slots:
@@ skipping 97 matching lines @@
     NORMALIZED_MAP_CACHE_INDEX,
     RUNTIME_CONTEXT_INDEX,
     CALL_AS_FUNCTION_DELEGATE_INDEX,
     CALL_AS_CONSTRUCTOR_DELEGATE_INDEX,
     SCRIPT_FUNCTION_INDEX,
     OPAQUE_REFERENCE_FUNCTION_INDEX,
     CONTEXT_EXTENSION_FUNCTION_INDEX,
     OUT_OF_MEMORY_INDEX,
     CONTEXT_DATA_INDEX,
     ALLOW_CODE_GEN_FROM_STRINGS_INDEX,
+    DERIVED_HAS_TRAP_INDEX,
     DERIVED_GET_TRAP_INDEX,
     DERIVED_SET_TRAP_INDEX,
 
     // Properties from here are treated as weak references by the full GC.
     // Scavenge treats them as strong references.
     OPTIMIZED_FUNCTIONS_LIST,  // Weak.
     MAP_CACHE_INDEX,  // Weak.
     NEXT_CONTEXT_LINK,  // Weak.
 
     // Total number of slots.
@@ skipping 145 matching lines @@
 #ifdef DEBUG
   // Bootstrapping-aware type checks.
   static bool IsBootstrappingOrContext(Object* object);
   static bool IsBootstrappingOrGlobalObject(Object* object);
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CONTEXTS_H_