Update ObjectToString to Harmony-draft algorithm

src/heap/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 
 #include "src/allocation.h"
@@ skipping 307 matching lines @@
   V(infinity_string, "Infinity")                           \
   V(minus_infinity_string, "-Infinity")                    \
   V(query_colon_string, "(?:)")                            \
   V(Generator_string, "Generator")                         \
   V(throw_string, "throw")                                 \
   V(done_string, "done")                                   \
   V(value_string, "value")                                 \
   V(next_string, "next")                                   \
   V(byte_length_string, "byteLength")                      \
   V(byte_offset_string, "byteOffset")                      \
-  V(minus_zero_string, "-0")
+  V(minus_zero_string, "-0")                               \
+  V(Array_string, "Array")                                 \
+  V(Error_string, "Error")                                 \
+  V(RegExp_string, "RegExp")
 
 #define PRIVATE_SYMBOL_LIST(V)      \
   V(frozen_symbol)                  \
   V(nonexistent_symbol)             \
   V(elements_transition_symbol)     \
   V(observed_symbol)                \
   V(uninitialized_symbol)           \
   V(megamorphic_symbol)             \
   V(premonomorphic_symbol)          \
   V(generic_symbol)                 \
@@ skipping 2202 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_