update spec.typeofSymbol references to es6.symbols

test/kangax.js

@@ -48,7 +48,7 @@ suite("kangax/compat-table", function () {
       code = transform(code, {
         filename: key,
         blacklist: ["strict"],
-        optional: ["spec.typeofSymbol", "es6.blockScopingTDZ"]
+        optional: ["es6.symbols", "es6.blockScopingTDZ"]
       }).code;
 
       code = '"use strict";\n' + code;

test/traceur.js

@@ -90,7 +90,7 @@ require("./_transformation-helper")({
     "Syntax/StrictKeywords"
   ]
 }, {
-  optional: ["spec.typeofSymbol"],
+  optional: ["es6.symbols"],
   experimental: true
 }, function (opts, task) {
   if (!_.contains(task.exec.loc, "module.js")) {