ES6 symbols: Implement Symbol intrinsic and basic functionality

src/type-info.cc

 // 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 249 matching lines @@
 }
 
 
 Handle<JSObject> TypeFeedbackOracle::GetPrototypeForPrimitiveCheck(
     CheckType check) {
   JSFunction* function = NULL;
   switch (check) {
     case RECEIVER_MAP_CHECK:
       UNREACHABLE();
       break;
+    case SYMBOL_CHECK:
+      return Handle<JSObject>(native_context_->symbol_delegate());
     case STRING_CHECK:
       function = native_context_->string_function();
       break;
     case NUMBER_CHECK:
       function = native_context_->number_function();
       break;
     case BOOLEAN_CHECK:
       function = native_context_->boolean_function();
       break;
   }
@@ skipping 432 matching lines @@
   USE(maybe_result);
 #ifdef DEBUG
   Object* result = NULL;
   // Dictionary has been allocated with sufficient size for all elements.
   ASSERT(maybe_result->ToObject(&result));
   ASSERT(*dictionary_ == result);
 #endif
 }
 
 } }  // namespace v8::internal