[WIP] NumberToString operator in TF.

src/heap-symbols.h

 // Copyright 2015 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_SYMBOLS_H_
 #define V8_HEAP_SYMBOLS_H_
 
 #define INTERNALIZED_STRING_LIST(V)                                \
   V(anonymous_string, "anonymous")                                 \
   V(apply_string, "apply")                                         \
@@ skipping 77 matching lines @@
   V(isExtensible_string, "isExtensible")                           \
   V(isView_string, "isView")                                       \
   V(KeyedLoadMonomorphic_string, "KeyedLoadMonomorphic")           \
   V(KeyedStoreMonomorphic_string, "KeyedStoreMonomorphic")         \
   V(last_index_string, "lastIndex")                                \
   V(length_string, "length")                                       \
   V(line_string, "line")                                           \
   V(Map_string, "Map")                                             \
   V(message_string, "message")                                     \
   V(minus_infinity_string, "-Infinity")                            \
+  V(zero_string, "0")                                              \
   V(minus_zero_string, "-0")                                       \
   V(name_string, "name")                                           \
   V(nan_string, "NaN")                                             \
   V(next_string, "next")                                           \
   V(not_equal, "not-equal")                                        \
   V(null_string, "null")                                           \
   V(null_to_string, "[object Null]")                               \
   V(number_string, "number")                                       \
   V(Number_string, "Number")                                       \
   V(object_string, "object")                                       \
@@ skipping 110 matching lines @@
 // Well-Known Symbols are "Public" symbols, which have a bit set which causes
 // them to produce an undefined value when a load results in a failed access
 // check. Because this behaviour is not specified properly as of yet, it only
 // applies to a subset of spec-defined Well-Known Symbols.
 #define WELL_KNOWN_SYMBOL_LIST(V)                           \
   V(has_instance_symbol, Symbol.hasInstance)                \
   V(is_concat_spreadable_symbol, Symbol.isConcatSpreadable) \
   V(to_string_tag_symbol, Symbol.toStringTag)
 
 #endif  // V8_HEAP_SYMBOLS_H_