Update ObjectToString to Harmony-draft algorithm

src/symbol.js

Index: src/symbol.js
diff --git a/src/symbol.js b/src/symbol.js
index e00979019010e93d47634b055725e8a68009179b..c3a7aa56aeb62bd120059511aa85a1da467b9f29 100644
--- a/src/symbol.js
+++ b/src/symbol.js
@@ -101,6 +101,7 @@ function SetUpSymbol() {
     // "isConcatSpreadable", symbolIsConcatSpreadable,
     // "isRegExp", symbolIsRegExp,
     "iterator", symbolIterator,
+    // TODO: Currently defined in harmony-tostring.js --- Move here when shipping

[Dmitry Lomov (no reviews), 2014/10/17 19:29:06]

nit: 80 column lines

[caitp (gmail), 2014/10/17 20:12:13]

Acknowledged.

     // "toStringTag", symbolToStringTag,
     "unscopables", symbolUnscopables
   ));
@@ -110,6 +111,8 @@ function SetUpSymbol() {
   ));
 
   %AddNamedProperty($Symbol.prototype, "constructor", $Symbol, DONT_ENUM);
+  %AddNamedProperty(
+      $Symbol.prototype, symbolToStringTag, "Symbol", DONT_ENUM | READ_ONLY);

[Dmitry Lomov (no reviews), 2014/10/17 19:29:06]

Hmm, when --harmony-tostring is turned off, where symbolToStringTag comes from?

Maybe better to move all these prototype modifications to harmony-tostring.js?

[caitp (gmail), 2014/10/17 20:12:13]

It's defined in both harmony-tostring.js and symbol.js --- InternalSymbol will
just return the existing symbol in the well known symbols registry if it already
exists, so this is fine.

It doesn't hurt to define the property regardless of whether the flag is enabled
or not, although I guess it's a bit of extra memory that never gets used if it's
not there

[Dmitry Lomov (no reviews), 2014/10/18 08:41:49]

Oh I see. missed that.
Yes, it is fine

   InstallFunctions($Symbol.prototype, DONT_ENUM, $Array(
     "toString", SymbolToString,
     "valueOf", SymbolValueOf