Add three string constants from parser to the root-set.

src/heap.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 191 matching lines @@
   V(proto_string, "__proto__")                                           \
   V(arguments_string, "arguments")                                       \
   V(Arguments_string, "Arguments")                                       \
   V(call_string, "call")                                                 \
   V(apply_string, "apply")                                               \
   V(caller_string, "caller")                                             \
   V(boolean_string, "boolean")                                           \
   V(Boolean_string, "Boolean")                                           \
   V(callee_string, "callee")                                             \
   V(constructor_string, "constructor")                                   \
-  V(result_string, ".result")                                            \
+  V(dot_result_string, ".result")                                        \
   V(dot_for_string, ".for.")                                             \
+  V(dot_iterator_string, ".iterator")                                    \
+  V(dot_generator_object_string, ".generator_object")                    \
   V(eval_string, "eval")                                                 \
   V(empty_string, "")                                                    \
   V(function_string, "function")                                         \
   V(length_string, "length")                                             \
   V(module_string, "module")                                             \
   V(name_string, "name")                                                 \
   V(native_string, "native")                                             \
   V(null_string, "null")                                                 \
   V(number_string, "number")                                             \
   V(Number_string, "Number")                                             \
@@ skipping 2847 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_